Motherboard Power Requirements

[arifi]

Hello everyone,

At work we wish to build a small-footprint demo computer using one of
those thin (10cm / 4 inches high) desktop cases, which will be easy to
carry to customer's sites, and such. We prefer this way rather than
buying a strong laptop since we believe such a system will perform
better and be more flexible.

The case we have found has a power suply capable of producing 230
Watts, and they claim it easily drives P4 systems. The case can house
microATX size MoBos. The power supply is a thin and long one custom for
this case, so there is no easy way to upgrade the PSU.

Being primarily an ASUS house, we searched for "microatx" and "matx" on
their web site, and the following motherboards were listed:

P5GD1-VM
P4GE-MX
P4R800-VM
P4P800-VM
P4BP-MX
P4S800-MX
P4SP-MX
P4SP-MX SE
P4V533-MX
P4VP-MX
A7N8X-VM
A7N8X-VM/400
P5S800-VM
K8S-MX

I would assume all to be nice boards, but we have not been able to find
conclusive information about how much Wattage the complete system built
around one ot them would require.

The system will contain the Motherboard, 2x512MB DDR RAM, 1x P4 CPU, 1x
SATA drive, CDROM Player, cabled keyboard and cabled mouse. No other
attachments except for a monitor or a projection device. The amount of
computing power we need is at the order of a P4-2800 with 1Meg Cache,
but we do know that we will have to settle with the max. that the power
supply can drive.

There are Power Supply calculators out there, but the ones I have
looked into do not consider all-in-one boards like the ones above where
the graphics card, lan etc are all on the motherboard.

So the Question is: How can I find out how much power these
motherboards will draw? What is the strongest CPU/MoBo combination I
can use with the 230W PS we have? (he system will be run at rated
speeds - no overclocking)

I will appreciate any information and any pointers deeply.

Many thanks in advance,
-arifi

 

[arifi]

Ah, I forgot to mentione - an AMD solution is also perfectly acceptable
if the Power/Wattage ratio is higher there.

Cheers,
-arifi

 

[Rob Stow]

Hello everyone,

At work we wish to build a small-footprint demo computer using one of
those thin (10cm / 4 inches high) desktop cases, which will be easy to
carry to customer's sites, and such. We prefer this way rather than
buying a strong laptop since we believe such a system will perform
better and be more flexible.

The case we have found has a power suply capable of producing 230
Watts, and they claim it easily drives P4 systems. The case can house
microATX size MoBos. The power supply is a thin and long one custom for
this case, so there is no easy way to upgrade the PSU.

Being primarily an ASUS house, we searched for "microatx" and "matx" on
their web site, and the following motherboards were listed:

P5GD1-VM
P4GE-MX
P4R800-VM
P4P800-VM
P4BP-MX
P4S800-MX
P4SP-MX
P4SP-MX SE
P4V533-MX
P4VP-MX
A7N8X-VM
A7N8X-VM/400
P5S800-VM
K8S-MX

I would assume all to be nice boards, but we have not been able to find
conclusive information about how much Wattage the complete system built
around one ot them would require.

The system will contain the Motherboard, 2x512MB DDR RAM, 1x P4 CPU, 1x
SATA drive, CDROM Player, cabled keyboard and cabled mouse. No other
attachments except for a monitor or a projection device. The amount of
computing power we need is at the order of a P4-2800 with 1Meg Cache,
but we do know that we will have to settle with the max. that the power
supply can drive.

There are Power Supply calculators out there, but the ones I have
looked into do not consider all-in-one boards like the ones above where
the graphics card, lan etc are all on the motherboard.

So the Question is: How can I find out how much power these
motherboards will draw? What is the strongest CPU/MoBo combination I
can use with the 230W PS we have? (he system will be run at rated
speeds - no overclocking)

I will appreciate any information and any pointers deeply.

Many thanks in advance,
-arifi

Why not a Pentium M based system ?

Lots of reviews available these days, including
http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2342

Use a P-M instead of a piece of crap like a P4 will go a long
ways to helping you meet your power bugdet. The downside is that
it will cost significantly more.

Also consider using an Athlon64 2800+, 3000+, or 3200+. Either
will outperform a P4-2800 in just about everything and will save
about 25W on your power requirements. The power savings involved
in using an Athlon64 are not as large as those of using a
Pentium-M, but it would be a lot easier on the wallet.

As well, I have built a couple of systems using the A7N8X-VM that
you listed, as well as the older A7N266-VM. Put a mobile Athlon
XP-M 2500+ into one of those and you should have no problem
meeting both your power budget and your performance target.

You also don't give the slightest hint about what this "demo
system" of yours is supposed to demonstrate. If all you need to
do is show video or run presentations, an EPIA M10000 from VIA
does the job nicely. I used one of those last fall to make a
fanless system - including using a fanless 150W PSU - for
someone. That system is used in a board room to show video and
do things like output PowerPoint to a projector.

www.quietpc.com would be worth checking out.

 

[Arifi Koseoglu]

Why not a Pentium M based system ?

Lots of reviews available these days, including
http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2342

Use a P-M instead of a piece of crap like a P4 will go a long ways to
helping you meet your power bugdet. The downside is that it will cost
significantly more.

Also consider using an Athlon64 2800+, 3000+, or 3200+. Either will
outperform a P4-2800 in just about everything and will save about 25W on
your power requirements. The power savings involved in using an Athlon64
are not as large as those of using a Pentium-M, but it would be a lot
easier on the wallet.

As well, I have built a couple of systems using the A7N8X-VM that you
listed, as well as the older A7N266-VM. Put a mobile Athlon XP-M 2500+
into one of those and you should have no problem meeting both your power
budget and your performance target.

You also don't give the slightest hint about what this "demo system" of
yours is supposed to demonstrate. If all you need to do is show video or
run presentations, an EPIA M10000 from VIA does the job nicely. I used
one of those last fall to make a fanless system - including using a
fanless 150W PSU - for someone. That system is used in a board room to
show video and do things like output PowerPoint to a projector.

www.quietpc.com would be worth checking out.

Hi Rob, and thanks for the information. I will look into the configurations
you mention - sadly the mobile versions are hard to find here except when in
a notebook ) .

And also, you are completely right about my not mentioning what the system
will be demoing - sorry - very important information. This system will be
running a Document Management and Workflow System along with a Webserver.
Well, although these seem like a lot of load, since the demos are done using
single-user scenarios, I do not expect any bottlenects other than the
performance of the Java engine behind the workflow and probably IIS.

Any other comments in light of this additional info ?

Thanks again,
-arifi

 

[Arifi Koseoglu]

Hi Rob, and thanks for the information. I will look into the
configurations you mention - sadly the mobile versions are hard to find
here except when in a notebook ) .

And also, you are completely right about my not mentioning what the system
will be demoing - sorry - very important information. This system will be
running a Document Management and Workflow System along with a Webserver.
Well, although these seem like a lot of load, since the demos are done
using single-user scenarios, I do not expect any bottlenects other than
the performance of the Java engine behind the workflow and probably IIS.

Any other comments in light of this additional info ?

Thanks again,
-arifi

Gosh! nowadays I type faster than I think: I forgot to mention that the
system will be running on Windows 2000 Server SP4 + Microsoft SQL Server
2000 SP3a.

Cheers
-arifi

 

[Paul]

Hello everyone,

At work we wish to build a small-footprint demo computer using one of
those thin (10cm / 4 inches high) desktop cases, which will be easy to
carry to customer's sites, and such. We prefer this way rather than
buying a strong laptop since we believe such a system will perform
better and be more flexible.

The case we have found has a power suply capable of producing 230
Watts, and they claim it easily drives P4 systems. The case can house
microATX size MoBos. The power supply is a thin and long one custom for
this case, so there is no easy way to upgrade the PSU.

Being primarily an ASUS house, we searched for "microatx" and "matx" on
their web site, and the following motherboards were listed:

P5GD1-VM
P4GE-MX
P4R800-VM
P4P800-VM
P4BP-MX
P4S800-MX
P4SP-MX
P4SP-MX SE
P4V533-MX
P4VP-MX
A7N8X-VM
A7N8X-VM/400
P5S800-VM
K8S-MX

I would assume all to be nice boards, but we have not been able to find
conclusive information about how much Wattage the complete system built
around one ot them would require.

The system will contain the Motherboard, 2x512MB DDR RAM, 1x P4 CPU, 1x
SATA drive, CDROM Player, cabled keyboard and cabled mouse. No other
attachments except for a monitor or a projection device. The amount of
computing power we need is at the order of a P4-2800 with 1Meg Cache,
but we do know that we will have to settle with the max. that the power
supply can drive.

There are Power Supply calculators out there, but the ones I have
looked into do not consider all-in-one boards like the ones above where
the graphics card, lan etc are all on the motherboard.

So the Question is: How can I find out how much power these
motherboards will draw? What is the strongest CPU/MoBo combination I
can use with the 230W PS we have? (he system will be run at rated
speeds - no overclocking)

I will appreciate any information and any pointers deeply.

Many thanks in advance,
-arifi

For power estimation purposes, you could go to the Intel motherboard
web page, and look at some boards there. Each board has a manual,
and there is a power estimate section.

http://developer.intel.com/design/motherbd/products.htm

This is the manual for the D915GAG (microATX builtin graphics)
These numbers are maximums, in every sense of the word.
I use these numbers only to get some idea of what the
non-CPU rails will be drawing.
ftp://download.intel.com/design/motherbd/ag/C6860002.pdf

Mode DC Power +3.3V +5V +12V -12V +5VSB
Minimum loading 200.00W 3.30A 10.00A 900mA 0.03A 0.80A
Maximum loading 300.00W 6.00A 14.00A 16.00A 0.10A 1.40A

Based on their description, start with the minimum loading
spec. Your two DIMMs will add about 5W each. The +12V
draw, exclusive of the processor, would be for fans.
A Prescott P4 2.8/FSB800/1MB LGA775 has a TDP of 84 watts
(see page 74 table 5-1).

ftp://download.intel.com/design/Pentium4/datashts/30235101.pdf

The 84W comes from +12V. The Vcore converter could be
considered to be 90% efficient (based on the fact that the
MOSFETs and toroids don't get warm to the touch). The
+12V current required is thus (84/12)*(1/0.90)=7.8A .
(A 2.8GHz/FSB800/512KB Northwood is 69.7W ==> 6.45A)

Adding this together, and assuming the DIMM power comes
from +3.3V (3 amps to give the requires 10 watts), gives
a Prescott based 2.8Ghz system with power of:

Mode DC Power +3.3V +5V +12V -12V +5VSB
Minimum loading --- 3.30A 10.00A 0.9A 0.03A 0.80A
DIMMs --- 3.0A --- --- --- ---
Processor --- --- --- 7.8A --- ---
Disk drive --- --- 1.0A 0.5A --- ---
CD/RW Drive --- --- 1.0A 1.5A --- ---
Total 212.6W 6.30A 12.0A 10.7A 0.03A 0.80A
(Fan current included in the 0.9A minimum)

This online calculator will also work out powers for you.
http://takaman.jp/D/?english

Other details. The hard drive will draw 2 amps from +12V
while spinning up. (Since the processor doesn't run at
full power in the BIOS, this is not an issue. On a
system I measured with my ammeter, CPU power might be
about 50% of max, while sitting in the BIOS as the drive
spins up.)

The CD/RW will only draw the 1.5 amp number while spinning
as well. Optical drive currents drop substantially when they
are not in use (no CD in drive). The listed hard drive
current might be representative of a seek operation.

You can find replacement supplies. But it won't be
easy.

http://www.pcpowerandcooling.com/prices/

There are a couple of 1U power supplies here. Due to the
small fan size, these will likely make a lot of noise
if you draw decent power from them.

http://www.pcpowerandcooling.com/products/power_supplies/highperformance/turbocools/index_hp_1u.htm

As Rob pointed out, there is a whole spectrum of power
saving solutions out there. But you'll need time to experiment
with them, to find the right one.

As for actual measured systems - these measurements are
exclusive of video card power. (My 9800pro video card
can draw [email protected] [email protected], but when the video card is
working that hard, the processor generally cannot run
at full power, due to waiting for the video card to
complete operations. A FX5200 low performance type video
card, would eliminate that extra power.) There is one hard
drive and one CD on these systems.

These two systems are roughly equal in gaming computing power.
A fast video card can add 38W to the power numbers. This shows
you how close a real system would get to your 230W total rating.
With a FX5200 class video card, you would be in good shape.

(Processor current comes from +5V...)
A7N8X-E 3200+ 2x512MB dual channel
[email protected] [email protected] [email protected] (running Prime95 = 106W)

(Processor current comes from +12V...)
P4C800-E 2.8G/FSB800/512K 2x512MB dual channel
[email protected] [email protected] [email protected] (running memtest86 = 113W)

The only thing that seems to be amiss, is Intel's user
manual estimates a large +5V consumption, and at least
with my P4C800-E, the power seems to come more from
+3.3V . This means, depending on which company makes the
motherboard, the same amount of power will be used, but
it could either be drawn heavily from +3.3V or +5V rail.

In the examples above, the AthlonXP board uses the +5V supply
to power the processor. Pentium4 and Athlon64 boards use
+12V to power the processor (that is why they both use the
2x2 power connector, for extra +12V current). Depending on
how the amps pan out on the various outputs of your power
supply, may help you decide whether a +5V powered processor
or a +12V powered processor, is the right answer.

As for Athlon64, the TDPs are listed here. Some of the
Athlon64's have very nice power numbers. Whether they will
work for you, really depends on whether your application mix
works well with Athlon64's strengths and weaknesses. If you
were building a gaming box, the Athlon64 would be the easy
choice.

http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/30430.pdf

HTH,
Paul

 

[Rob Stow]

Hi Rob, and thanks for the information. I will look into the configurations
you mention - sadly the mobile versions are hard to find here except when in
a notebook ) .

I never have trouble finding a mobile Athlon XP at www.ncix.com -
at least on the Canadian side of their web site.
The also have a couple of Socket 479 boards for the Pentium-M
(and there really are only two options at the moment) but I had
no luck a few weeks ago when I tried to get a P-M processor from
them.

www.lynncomp.com has both XP-M and Pentium-M processors, as well
as motherboards for both.

And also, you are completely right about my not mentioning what the system
will be demoing - sorry - very important information. This system will be
running a Document Management and Workflow System along with a Webserver.
Well, although these seem like a lot of load, since the demos are done using
single-user scenarios, I do not expect any bottlenects other than the
performance of the Java engine behind the workflow and probably IIS.

Any other comments in light of this additional info ?

Yeah - forget about the EPIA option.
Not enough horsepower.

 

[Arifi Koseoglu]

For power estimation purposes, you could go to the Intel motherboard
web page, and look at some boards there. Each board has a manual,
and there is a power estimate section.

http://developer.intel.com/design/motherbd/products.htm

This is the manual for the D915GAG (microATX builtin graphics)
These numbers are maximums, in every sense of the word.
I use these numbers only to get some idea of what the
non-CPU rails will be drawing.
ftp://download.intel.com/design/motherbd/ag/C6860002.pdf

Mode DC Power +3.3V +5V +12V -12V +5VSB
Minimum loading 200.00W 3.30A 10.00A 900mA 0.03A 0.80A
Maximum loading 300.00W 6.00A 14.00A 16.00A 0.10A 1.40A

Based on their description, start with the minimum loading
spec. Your two DIMMs will add about 5W each. The +12V
draw, exclusive of the processor, would be for fans.
A Prescott P4 2.8/FSB800/1MB LGA775 has a TDP of 84 watts
(see page 74 table 5-1).

ftp://download.intel.com/design/Pentium4/datashts/30235101.pdf

The 84W comes from +12V. The Vcore converter could be
considered to be 90% efficient (based on the fact that the
MOSFETs and toroids don't get warm to the touch). The
+12V current required is thus (84/12)*(1/0.90)=7.8A .
(A 2.8GHz/FSB800/512KB Northwood is 69.7W ==> 6.45A)

Adding this together, and assuming the DIMM power comes
from +3.3V (3 amps to give the requires 10 watts), gives
a Prescott based 2.8Ghz system with power of:

Mode DC Power +3.3V +5V +12V -12V +5VSB
Minimum loading --- 3.30A 10.00A 0.9A 0.03A 0.80A
DIMMs --- 3.0A --- --- --- ---
Processor --- --- --- 7.8A --- ---
Disk drive --- --- 1.0A 0.5A --- ---
CD/RW Drive --- --- 1.0A 1.5A --- ---
Total 212.6W 6.30A 12.0A 10.7A 0.03A 0.80A
(Fan current included in the 0.9A minimum)

This online calculator will also work out powers for you.
http://takaman.jp/D/?english

Other details. The hard drive will draw 2 amps from +12V
while spinning up. (Since the processor doesn't run at
full power in the BIOS, this is not an issue. On a
system I measured with my ammeter, CPU power might be
about 50% of max, while sitting in the BIOS as the drive
spins up.)

The CD/RW will only draw the 1.5 amp number while spinning
as well. Optical drive currents drop substantially when they
are not in use (no CD in drive). The listed hard drive
current might be representative of a seek operation.

You can find replacement supplies. But it won't be
easy.

http://www.pcpowerandcooling.com/prices/

There are a couple of 1U power supplies here. Due to the
small fan size, these will likely make a lot of noise
if you draw decent power from them.

http://www.pcpowerandcooling.com/products/power_supplies/highperformance/turbocools/index_hp_1u.htm

As Rob pointed out, there is a whole spectrum of power
saving solutions out there. But you'll need time to experiment
with them, to find the right one.

As for actual measured systems - these measurements are
exclusive of video card power. (My 9800pro video card
can draw [email protected] [email protected], but when the video card is
working that hard, the processor generally cannot run
at full power, due to waiting for the video card to
complete operations. A FX5200 low performance type video
card, would eliminate that extra power.) There is one hard
drive and one CD on these systems.

These two systems are roughly equal in gaming computing power.
A fast video card can add 38W to the power numbers. This shows
you how close a real system would get to your 230W total rating.
With a FX5200 class video card, you would be in good shape.

(Processor current comes from +5V...)
A7N8X-E 3200+ 2x512MB dual channel
[email protected] [email protected] [email protected] (running Prime95 = 106W)

(Processor current comes from +12V...)
P4C800-E 2.8G/FSB800/512K 2x512MB dual channel
[email protected] [email protected] [email protected] (running memtest86 = 113W)

The only thing that seems to be amiss, is Intel's user
manual estimates a large +5V consumption, and at least
with my P4C800-E, the power seems to come more from
+3.3V . This means, depending on which company makes the
motherboard, the same amount of power will be used, but
it could either be drawn heavily from +3.3V or +5V rail.

In the examples above, the AthlonXP board uses the +5V supply
to power the processor. Pentium4 and Athlon64 boards use
+12V to power the processor (that is why they both use the
2x2 power connector, for extra +12V current). Depending on
how the amps pan out on the various outputs of your power
supply, may help you decide whether a +5V powered processor
or a +12V powered processor, is the right answer.

As for Athlon64, the TDPs are listed here. Some of the
Athlon64's have very nice power numbers. Whether they will
work for you, really depends on whether your application mix
works well with Athlon64's strengths and weaknesses. If you
were building a gaming box, the Athlon64 would be the easy
choice.

http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/30430.pdf

HTH,
Paul

Dear Paul,

Hello again, and of course MANY MANY THANKS for the (once again) very much
detailed information.

After reading your post, the case I mentioned actually arrived and I had the
chance to look at the actual label on the power supply: First of all, the
PSU has a label stating that it is a 350W PSU and not a 230W as we were told
by the supplier. HOWEVER, the ratings on the label are as follows:

-----------------------------------------------
+3.3V | +5V | +12V | -5V | -12V | +5VSB
7A | 13A | 6A | 0.5A | 0.8A | 1A
-----------------------------------------------
75W Max |-------| 9.6 W Max |-------
-----------------------------------------------
3 5 0 W
-----------------------------------------------

Now, here is how I interpret the label:

1. The 75W Max. under the +3.3V & +5V columns probably means that the
combined simultaneous load on these lines cannot exceed 75Watts, while the
+3.3V line can carry 3.3x7=23.1W and the +5V line 5x13=65W.

2. The +12V line is capable of producing 12x6=72W.

3. The 9.6W Max. under the -5V & -12V columns probably means that the
combined simultaneous load on these lines cannot exceed 9.6Watts, while
the -5V line can carry 5x0.5=2.5W and the -12V line 12x0.8=9.6W. Prescott
based 2.8Ghz

4. The +5VSB line is capable of producing 5x1=5W. (By the way, what does VSB
mean?)

5. Taking into account the 75W and 9.6W Maximums, and adding the +12V and
+5VSB powers, I calculate the actual total power to be 75 + 9.6 + (72) + (5)
= 161.6W YUCK !!! Is this calculation correct?? Where is the claimed 350W ??

You mention that the P4 and Athlon64 get their CPU power from the +12V line,
while the AthlonXP from the +5V line. The P42.8Prescott has a TDP of 84Watts
(your post) and the Athlon64 3000+ a Max. TDP of 89Watts (Athlon64 Power and
Thermal Data Sheet.)

Does that now mean that I cannot run either of these CPUs using this PSU or
am I missing something?

Under what conditions are the maximum Power levels reached? Typical loading
of CPU on the Demo system will be a sequence like [Short/Intermediate
Peak] - [Longer Idle] - [Short Peak] - [Longer Idle] - [Short/Intermediate
Peak] - [Longer Idle] ...

Here comes where I get confused again. In your post you mention:

(Processor current comes from +5V...)
A7N8X-E 3200+ 2x512MB dual channel
[email protected] [email protected] [email protected] (running Prime95 = 106W)

(Processor current comes from +12V...)
P4C800-E 2.8G/FSB800/512K 2x512MB dual channel
[email protected] [email protected] [email protected] (running memtest86 = 113W)

Here you calculate the total Wattage by collecting values from all rails
(3.3, 5, 12). Then probably I should not expect all the CPU power from the
12V rail alone in the Athlon64 and Prescott cases... If so, I could still
use and Athlon64 or Prescott... But in your table you had put the 7.8A for
the CPU completely on the 12V line of the Prescott based 2.8Ghz system...Or
??

Confused... I hope I am not asking the obvious.

Many Thanks,
Cheers,
-arifi

 

[Paul]

For power estimation purposes, you could go to the Intel motherboard
web page, and look at some boards there. Each board has a manual,
and there is a power estimate section.

http://developer.intel.com/design/motherbd/products.htm

This is the manual for the D915GAG (microATX builtin graphics)
These numbers are maximums, in every sense of the word.
I use these numbers only to get some idea of what the
non-CPU rails will be drawing.
ftp://download.intel.com/design/motherbd/ag/C6860002.pdf

Mode DC Power +3.3V +5V +12V -12V +5VSB
Minimum loading 200.00W 3.30A 10.00A 900mA 0.03A 0.80A
Maximum loading 300.00W 6.00A 14.00A 16.00A 0.10A 1.40A

Based on their description, start with the minimum loading
spec. Your two DIMMs will add about 5W each. The +12V
draw, exclusive of the processor, would be for fans.
A Prescott P4 2.8/FSB800/1MB LGA775 has a TDP of 84 watts
(see page 74 table 5-1).

ftp://download.intel.com/design/Pentium4/datashts/30235101.pdf

The 84W comes from +12V. The Vcore converter could be
considered to be 90% efficient (based on the fact that the
MOSFETs and toroids don't get warm to the touch). The
+12V current required is thus (84/12)*(1/0.90)=7.8A .
(A 2.8GHz/FSB800/512KB Northwood is 69.7W ==> 6.45A)

Adding this together, and assuming the DIMM power comes
from +3.3V (3 amps to give the requires 10 watts), gives
a Prescott based 2.8Ghz system with power of:

Mode DC Power +3.3V +5V +12V -12V +5VSB
Minimum loading --- 3.30A 10.00A 0.9A 0.03A 0.80A
DIMMs --- 3.0A --- --- --- ---
Processor --- --- --- 7.8A --- ---
Disk drive --- --- 1.0A 0.5A --- ---
CD/RW Drive --- --- 1.0A 1.5A --- ---
Total 212.6W 6.30A 12.0A 10.7A 0.03A 0.80A
(Fan current included in the 0.9A minimum)

This online calculator will also work out powers for you.
http://takaman.jp/D/?english

Other details. The hard drive will draw 2 amps from +12V
while spinning up. (Since the processor doesn't run at
full power in the BIOS, this is not an issue. On a
system I measured with my ammeter, CPU power might be
about 50% of max, while sitting in the BIOS as the drive
spins up.)

The CD/RW will only draw the 1.5 amp number while spinning
as well. Optical drive currents drop substantially when they
are not in use (no CD in drive). The listed hard drive
current might be representative of a seek operation.

You can find replacement supplies. But it won't be
easy.

http://www.pcpowerandcooling.com/prices/

There are a couple of 1U power supplies here. Due to the
small fan size, these will likely make a lot of noise
if you draw decent power from them.

http://www.pcpowerandcooling.com/products/power_supplies/highperformance/turbocools/index_hp_1u.htm

As Rob pointed out, there is a whole spectrum of power
saving solutions out there. But you'll need time to experiment
with them, to find the right one.

As for actual measured systems - these measurements are
exclusive of video card power. (My 9800pro video card
can draw [email protected] [email protected], but when the video card is
working that hard, the processor generally cannot run
at full power, due to waiting for the video card to
complete operations. A FX5200 low performance type video
card, would eliminate that extra power.) There is one hard
drive and one CD on these systems.

These two systems are roughly equal in gaming computing power.
A fast video card can add 38W to the power numbers. This shows
you how close a real system would get to your 230W total rating.
With a FX5200 class video card, you would be in good shape.

(Processor current comes from +5V...)
A7N8X-E 3200+ 2x512MB dual channel
[email protected] [email protected] [email protected] (running Prime95 = 106W)

(Processor current comes from +12V...)
P4C800-E 2.8G/FSB800/512K 2x512MB dual channel
[email protected] [email protected] [email protected] (running memtest86 = 113W)

The only thing that seems to be amiss, is Intel's user
manual estimates a large +5V consumption, and at least
with my P4C800-E, the power seems to come more from
+3.3V . This means, depending on which company makes the
motherboard, the same amount of power will be used, but
it could either be drawn heavily from +3.3V or +5V rail.

In the examples above, the AthlonXP board uses the +5V supply
to power the processor. Pentium4 and Athlon64 boards use
+12V to power the processor (that is why they both use the
2x2 power connector, for extra +12V current). Depending on
how the amps pan out on the various outputs of your power
supply, may help you decide whether a +5V powered processor
or a +12V powered processor, is the right answer.

As for Athlon64, the TDPs are listed here. Some of the
Athlon64's have very nice power numbers. Whether they will
work for you, really depends on whether your application mix
works well with Athlon64's strengths and weaknesses. If you
were building a gaming box, the Athlon64 would be the easy
choice.

http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/30430.pdf

HTH,
Paul

Dear Paul,

Hello again, and of course MANY MANY THANKS for the (once again) very much
detailed information.

After reading your post, the case I mentioned actually arrived and I had the
chance to look at the actual label on the power supply: First of all, the
PSU has a label stating that it is a 350W PSU and not a 230W as we were told
by the supplier. HOWEVER, the ratings on the label are as follows:

-----------------------------------------------
+3.3V | +5V | +12V | -5V | -12V | +5VSB
7A | 13A | 6A | 0.5A | 0.8A | 1A
-----------------------------------------------
75W Max |-------| 9.6 W Max |-------
-----------------------------------------------
3 5 0 W
-----------------------------------------------

Now, here is how I interpret the label:

1. The 75W Max. under the +3.3V & +5V columns probably means that the
combined simultaneous load on these lines cannot exceed 75Watts, while the
+3.3V line can carry 3.3x7=23.1W and the +5V line 5x13=65W.

2. The +12V line is capable of producing 12x6=72W.

3. The 9.6W Max. under the -5V & -12V columns probably means that the
combined simultaneous load on these lines cannot exceed 9.6Watts, while
the -5V line can carry 5x0.5=2.5W and the -12V line 12x0.8=9.6W. Prescott
based 2.8Ghz

4. The +5VSB line is capable of producing 5x1=5W. (By the way, what does VSB
mean?)

5. Taking into account the 75W and 9.6W Maximums, and adding the +12V and
+5VSB powers, I calculate the actual total power to be 75 + 9.6 + (72) + (5)
= 161.6W YUCK !!! Is this calculation correct?? Where is the claimed 350W ??

You mention that the P4 and Athlon64 get their CPU power from the +12V line,
while the AthlonXP from the +5V line. The P42.8Prescott has a TDP of 84Watts
(your post) and the Athlon64 3000+ a Max. TDP of 89Watts (Athlon64 Power and
Thermal Data Sheet.)

Does that now mean that I cannot run either of these CPUs using this PSU or
am I missing something?

Under what conditions are the maximum Power levels reached? Typical loading
of CPU on the Demo system will be a sequence like [Short/Intermediate
Peak] - [Longer Idle] - [Short Peak] - [Longer Idle] - [Short/Intermediate
Peak] - [Longer Idle] ...

Here comes where I get confused again. In your post you mention:

(Processor current comes from +5V...)
A7N8X-E 3200+ 2x512MB dual channel
[email protected] [email protected] [email protected] (running Prime95 = 106W)

(Processor current comes from +12V...)
P4C800-E 2.8G/FSB800/512K 2x512MB dual channel
[email protected] [email protected] [email protected] (running memtest86 = 113W)

Here you calculate the total Wattage by collecting values from all rails
(3.3, 5, 12). Then probably I should not expect all the CPU power from the
12V rail alone in the Athlon64 and Prescott cases... If so, I could still
use and Athlon64 or Prescott... But in your table you had put the 7.8A for
the CPU completely on the 12V line of the Prescott based 2.8Ghz system...Or
??

Confused... I hope I am not asking the obvious.

Many Thanks,
Cheers,
-arifi

That has got to be the worst power supply I've ever seen.

Are you sure that isn't the *minimum* load ? Some supplies
have two sets of number, some minimum numbers and some
maximum numbers. The power supply will not regulate to
within 5% of nominal output voltage, unless the minimum
load is applied.

Is it possible for you to give more info about the
case and power supply you bought ? Do you have a
URL for a website, with details about the product,
and maybe a picture of the label on the power supply ?

I think you understand the basic principles. The power
supply has limits for the maximum current that can
come from any individual output, and there are also
limits for certain groups of outputs. The group limits
are caused by using a multi-winding transformer in the
output. If two windings are supplying current, the thermal
load on the transformer will bear some relationship to that
load. Thus, the label on the power supply will state a
combined total power for those outputs. The total power for
the power supply should also be based on some fundamental
limit of the supply (maybe the rating of the primary side
and switching components ?). In any case, all those limits
apply simultaneously, so you cannot exceed any output's
maximum current, neither can you exceed one of the group
power ratings.

If the ratings on that label are for real, you've got enough
power *maybe* for a Pentium-M or a Via EPIA. There isn't
enough current available on +5V or +12V to run any of the
motherboards I've got here (my home collection).

So, work on verifying that label.

The +5VSB stands for +5 volts standby. The +5VSB supply
continues to run when the computer is in S3 Standby. The
suspend to RAM function requires power to keep the memory
chips refreshed, and that comes from +5VSB. The +5VSB is
also used for any Wake on LAN, Wake on Ring, or similar
functions, that require portions of the other chips to be
operational while the computer is in standby. These days,
2 amps is a good number for +5VSB. If you only have
one amp to work with, then all wake functions and any
USB/keyboard header settings must be set not to use +5VSB.

My measurements for my A7N8X-E and P4C800-E were done with
a clamp-on DC ammeter. This is a device based on a Hall
probe, that converts the magnetic field around a conductor
into a voltage. My meter will measure AC or DC current in
a conductor, by simply clamping the meter around a
conductor or a group of conductors (the magnetic fields add).

This is how I measured my home systems. You grab all the +5V
wires on the ATX 20 pin power cable and put them in the jaws
of one of these, then measure the current flowing in the
bundle of wires. Useful for determining how close to the
limits you are. Mine cost $400 Canadian.

http://www.extechproducts.com/products/extech/380941_942_947.pdf

Paul

 

[Arifi Koseoglu]

Hello everyone,

At work we wish to build a small-footprint demo computer using one of
those thin (10cm / 4 inches high) desktop cases, which will be easy to
carry to customer's sites, and such. We prefer this way rather than
buying a strong laptop since we believe such a system will perform
better and be more flexible.

The case we have found has a power suply capable of producing 230
Watts, and they claim it easily drives P4 systems. The case can house
microATX size MoBos. The power supply is a thin and long one custom
for
this case, so there is no easy way to upgrade the PSU.

Being primarily an ASUS house, we searched for "microatx" and "matx"
on
their web site, and the following motherboards were listed:

P5GD1-VM
P4GE-MX
P4R800-VM
P4P800-VM
P4BP-MX
P4S800-MX
P4SP-MX
P4SP-MX SE
P4V533-MX
P4VP-MX
A7N8X-VM
A7N8X-VM/400
P5S800-VM
K8S-MX

I would assume all to be nice boards, but we have not been able to
find
conclusive information about how much Wattage the complete system
built
around one ot them would require.

The system will contain the Motherboard, 2x512MB DDR RAM, 1x P4 CPU,
1x
SATA drive, CDROM Player, cabled keyboard and cabled mouse. No other
attachments except for a monitor or a projection device. The amount of
computing power we need is at the order of a P4-2800 with 1Meg Cache,
but we do know that we will have to settle with the max. that the
power
supply can drive.

There are Power Supply calculators out there, but the ones I have
looked into do not consider all-in-one boards like the ones above
where
the graphics card, lan etc are all on the motherboard.

So the Question is: How can I find out how much power these
motherboards will draw? What is the strongest CPU/MoBo combination I
can use with the 230W PS we have? (he system will be run at rated
speeds - no overclocking)

I will appreciate any information and any pointers deeply.

Many thanks in advance,
-arifi

For power estimation purposes, you could go to the Intel motherboard
web page, and look at some boards there. Each board has a manual,
and there is a power estimate section.

http://developer.intel.com/design/motherbd/products.htm

This is the manual for the D915GAG (microATX builtin graphics)
These numbers are maximums, in every sense of the word.
I use these numbers only to get some idea of what the
non-CPU rails will be drawing.
ftp://download.intel.com/design/motherbd/ag/C6860002.pdf

Mode DC Power +3.3V +5V +12V -12V +5VSB
Minimum loading 200.00W 3.30A 10.00A 900mA 0.03A 0.80A
Maximum loading 300.00W 6.00A 14.00A 16.00A 0.10A 1.40A

Based on their description, start with the minimum loading
spec. Your two DIMMs will add about 5W each. The +12V
draw, exclusive of the processor, would be for fans.
A Prescott P4 2.8/FSB800/1MB LGA775 has a TDP of 84 watts
(see page 74 table 5-1).

ftp://download.intel.com/design/Pentium4/datashts/30235101.pdf

The 84W comes from +12V. The Vcore converter could be
considered to be 90% efficient (based on the fact that the
MOSFETs and toroids don't get warm to the touch). The
+12V current required is thus (84/12)*(1/0.90)=7.8A .
(A 2.8GHz/FSB800/512KB Northwood is 69.7W ==> 6.45A)

Adding this together, and assuming the DIMM power comes
from +3.3V (3 amps to give the requires 10 watts), gives
a Prescott based 2.8Ghz system with power of:

Mode DC Power +3.3V +5V +12V -12V +5VSB
Minimum loading --- 3.30A 10.00A 0.9A 0.03A 0.80A
DIMMs --- 3.0A --- --- --- ---
Processor --- --- --- 7.8A --- ---
Disk drive --- --- 1.0A 0.5A --- ---
CD/RW Drive --- --- 1.0A 1.5A --- ---
Total 212.6W 6.30A 12.0A 10.7A 0.03A 0.80A
(Fan current included in the 0.9A minimum)

This online calculator will also work out powers for you.
http://takaman.jp/D/?english

Other details. The hard drive will draw 2 amps from +12V
while spinning up. (Since the processor doesn't run at
full power in the BIOS, this is not an issue. On a
system I measured with my ammeter, CPU power might be
about 50% of max, while sitting in the BIOS as the drive
spins up.)

The CD/RW will only draw the 1.5 amp number while spinning
as well. Optical drive currents drop substantially when they
are not in use (no CD in drive). The listed hard drive
current might be representative of a seek operation.

You can find replacement supplies. But it won't be
easy.

http://www.pcpowerandcooling.com/prices/

There are a couple of 1U power supplies here. Due to the
small fan size, these will likely make a lot of noise
if you draw decent power from them.

http://www.pcpowerandcooling.com/products/power_supplies/highperformance/turbocools/index_hp_1u.htm

As Rob pointed out, there is a whole spectrum of power
saving solutions out there. But you'll need time to experiment
with them, to find the right one.

As for actual measured systems - these measurements are
exclusive of video card power. (My 9800pro video card
can draw [email protected] [email protected], but when the video card is
working that hard, the processor generally cannot run
at full power, due to waiting for the video card to
complete operations. A FX5200 low performance type video
card, would eliminate that extra power.) There is one hard
drive and one CD on these systems.

These two systems are roughly equal in gaming computing power.
A fast video card can add 38W to the power numbers. This shows
you how close a real system would get to your 230W total rating.
With a FX5200 class video card, you would be in good shape.

(Processor current comes from +5V...)
A7N8X-E 3200+ 2x512MB dual channel
[email protected] [email protected] [email protected] (running Prime95 = 106W)

(Processor current comes from +12V...)
P4C800-E 2.8G/FSB800/512K 2x512MB dual channel
[email protected] [email protected] [email protected] (running memtest86 = 113W)

The only thing that seems to be amiss, is Intel's user
manual estimates a large +5V consumption, and at least
with my P4C800-E, the power seems to come more from
+3.3V . This means, depending on which company makes the
motherboard, the same amount of power will be used, but
it could either be drawn heavily from +3.3V or +5V rail.

In the examples above, the AthlonXP board uses the +5V supply
to power the processor. Pentium4 and Athlon64 boards use
+12V to power the processor (that is why they both use the
2x2 power connector, for extra +12V current). Depending on
how the amps pan out on the various outputs of your power
supply, may help you decide whether a +5V powered processor
or a +12V powered processor, is the right answer.

As for Athlon64, the TDPs are listed here. Some of the
Athlon64's have very nice power numbers. Whether they will
work for you, really depends on whether your application mix
works well with Athlon64's strengths and weaknesses. If you
were building a gaming box, the Athlon64 would be the easy
choice.

http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/30430.pdf

HTH,
Paul

Dear Paul,

Hello again, and of course MANY MANY THANKS for the (once again) very
much
detailed information.

After reading your post, the case I mentioned actually arrived and I had
the
chance to look at the actual label on the power supply: First of all, the
PSU has a label stating that it is a 350W PSU and not a 230W as we were
told
by the supplier. HOWEVER, the ratings on the label are as follows:

-----------------------------------------------
+3.3V | +5V | +12V | -5V | -12V | +5VSB
7A | 13A | 6A | 0.5A | 0.8A | 1A
-----------------------------------------------
75W Max |-------| 9.6 W Max |-------
-----------------------------------------------
3 5 0 W
-----------------------------------------------

Now, here is how I interpret the label:

1. The 75W Max. under the +3.3V & +5V columns probably means that the
combined simultaneous load on these lines cannot exceed 75Watts, while
the
+3.3V line can carry 3.3x7=23.1W and the +5V line 5x13=65W.

2. The +12V line is capable of producing 12x6=72W.

3. The 9.6W Max. under the -5V & -12V columns probably means that the
combined simultaneous load on these lines cannot exceed 9.6Watts, while
the -5V line can carry 5x0.5=2.5W and the -12V line 12x0.8=9.6W. Prescott
based 2.8Ghz

4. The +5VSB line is capable of producing 5x1=5W. (By the way, what does
VSB
mean?)

5. Taking into account the 75W and 9.6W Maximums, and adding the +12V and
+5VSB powers, I calculate the actual total power to be 75 + 9.6 + (72) +
(5)
= 161.6W YUCK !!! Is this calculation correct?? Where is the claimed 350W
??

You mention that the P4 and Athlon64 get their CPU power from the +12V
line,
while the AthlonXP from the +5V line. The P42.8Prescott has a TDP of
84Watts
(your post) and the Athlon64 3000+ a Max. TDP of 89Watts (Athlon64 Power
and
Thermal Data Sheet.)

Does that now mean that I cannot run either of these CPUs using this PSU
or
am I missing something?

Under what conditions are the maximum Power levels reached? Typical
loading
of CPU on the Demo system will be a sequence like [Short/Intermediate
Peak] - [Longer Idle] - [Short Peak] - [Longer Idle] -
[Short/Intermediate
Peak] - [Longer Idle] ...

Here comes where I get confused again. In your post you mention:

(Processor current comes from +5V...)
A7N8X-E 3200+ 2x512MB dual channel
[email protected] [email protected] [email protected] (running Prime95 = 106W)

(Processor current comes from +12V...)
P4C800-E 2.8G/FSB800/512K 2x512MB dual channel
[email protected] [email protected] [email protected] (running memtest86 = 113W)

Here you calculate the total Wattage by collecting values from all rails
(3.3, 5, 12). Then probably I should not expect all the CPU power from
the
12V rail alone in the Athlon64 and Prescott cases... If so, I could still
use and Athlon64 or Prescott... But in your table you had put the 7.8A
for
the CPU completely on the 12V line of the Prescott based 2.8Ghz
system...Or
??

Confused... I hope I am not asking the obvious.

Many Thanks,
Cheers,
-arifi

That has got to be the worst power supply I've ever seen.

Are you sure that isn't the *minimum* load ? Some supplies
have two sets of number, some minimum numbers and some
maximum numbers. The power supply will not regulate to
within 5% of nominal output voltage, unless the minimum
load is applied.

Is it possible for you to give more info about the
case and power supply you bought ? Do you have a
URL for a website, with details about the product,
and maybe a picture of the label on the power supply ?

I think you understand the basic principles. The power
supply has limits for the maximum current that can
come from any individual output, and there are also
limits for certain groups of outputs. The group limits
are caused by using a multi-winding transformer in the
output. If two windings are supplying current, the thermal
load on the transformer will bear some relationship to that
load. Thus, the label on the power supply will state a
combined total power for those outputs. The total power for
the power supply should also be based on some fundamental
limit of the supply (maybe the rating of the primary side
and switching components ?). In any case, all those limits
apply simultaneously, so you cannot exceed any output's
maximum current, neither can you exceed one of the group
power ratings.

If the ratings on that label are for real, you've got enough
power *maybe* for a Pentium-M or a Via EPIA. There isn't
enough current available on +5V or +12V to run any of the
motherboards I've got here (my home collection).

So, work on verifying that label.

The +5VSB stands for +5 volts standby. The +5VSB supply
continues to run when the computer is in S3 Standby. The
suspend to RAM function requires power to keep the memory
chips refreshed, and that comes from +5VSB. The +5VSB is
also used for any Wake on LAN, Wake on Ring, or similar
functions, that require portions of the other chips to be
operational while the computer is in standby. These days,
2 amps is a good number for +5VSB. If you only have
one amp to work with, then all wake functions and any
USB/keyboard header settings must be set not to use +5VSB.

My measurements for my A7N8X-E and P4C800-E were done with
a clamp-on DC ammeter. This is a device based on a Hall
probe, that converts the magnetic field around a conductor
into a voltage. My meter will measure AC or DC current in
a conductor, by simply clamping the meter around a
conductor or a group of conductors (the magnetic fields add).

This is how I measured my home systems. You grab all the +5V
wires on the ATX 20 pin power cable and put them in the jaws
of one of these, then measure the current flowing in the
bundle of wires. Useful for determining how close to the
limits you are. Mine cost $400 Canadian.

http://www.extechproducts.com/products/extech/380941_942_947.pdf

Paul

Dear Paul,

The web site of the company producing (actually, importing from China) the
case does not have any details on the PSU, so I removed the PSU from the
case, scanned the three sides on which the label was wrapped, combined the
three images and put the file on our web site:

http://www.mind2biz.com/download/codegen_psu_label.jpg

The case's web page is:

http://www.codegen.com.tr/desktop/ms-2.htm

We have the MS2-G7, which is the same as the MS2-G10 except for the color.
Some translation for the Turkish terms on that page (not that you wouldn't
be able to figure it out): "Boyutlar" means "Dimensions", "Surucu Yuvalari"
means "Drive Bays" and "Ses & Mikrofon" means "Sound and Microphone"

The actual dimensions of the PSU, if relevant, are 45mm x 80mm x 220mm (1.8"
x 3.2" x 8.8") (WxHxD), and it has two 4cm (1.6") fans, one one each end.

Here we have 220V/50Hz mains.

Pentium-M is hard to find here and importing from outside Turkey has too
much paperwork and extra costs attached. Of course, another case could be an
option, but strangely, this brand is the only one supplying these "slim"
ones and portability is also a factor.

Now, assuming that the information on the label's picture will not bring any
good news (but hoping for the opposite), should ve resort to plain AthlonXPs
and older P4s? For example, AMD documentation
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26237.PDF
states that an AthlonXP 2800+ draws a max. of 68.3W, which is just slightly
above the 65Watts that can be drawn (according to its label) from the +5V
line of this PSU. Similar options may be available for the P4 family too...

When is the "Max" power needed? When the CPU is running at 100% capacity
according to Windows Task Manager, is it also drawing the max. current /
power from the PSU? Is the duration a factor here?

Many thanks *again*,
Best,
-arifi

 

[Ed]

Now, assuming that the information on the label's picture will not bring any
good news (but hoping for the opposite), should ve resort to plain AthlonXPs
and older P4s? For example, AMD documentation
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26237.PDF
states that an AthlonXP 2800+ draws a max. of 68.3W, which is just slightly
above the 65Watts that can be drawn (according to its label) from the +5V
line of this PSU. Similar options may be available for the P4 family too...

AMD XP and Intel P4 use the 12V line for their main power, I doubt 6A on
the 12V line is going to cut it. My Enlight 300W PSU has 10A on the 12V
line and can run a Barton 2800+ w/1 HDD + low end grafix card, anything
faster and it needs more power. I just put an Antec 400w (12V @ 18A) in
it and now it runs @ 3200+ (and faster 2.4GHz) no problem.

Ed

 

[Lenny Nero]

In

Hello everyone,

At work we wish to build a small-footprint demo computer using one of
those thin (10cm / 4 inches high) desktop cases, which will be easy to
carry to customer's sites, and such. We prefer this way rather than
buying a strong laptop since we believe such a system will perform
better and be more flexible.

The case we have found has a power suply capable of producing 230
Watts, and they claim it easily drives P4 systems. The case can house
microATX size MoBos. The power supply is a thin and long one custom
for this case, so there is no easy way to upgrade the PSU.

Being primarily an ASUS house, we searched for "microatx" and "matx"
on their web site, and the following motherboards were listed:

A7N8X-VM/400

[...]

Many thanks in advance,
-arifi

Just to let you know,
I have built a SFF PC around an A7N8X-VM/400 with an AMD processor and am
very happy with it.

L.

 

[Paul]

Dear Paul,

The web site of the company producing (actually, importing from China) the
case does not have any details on the PSU, so I removed the PSU from the
case, scanned the three sides on which the label was wrapped, combined the
three images and put the file on our web site:

http://www.mind2biz.com/download/codegen_psu_label.jpg

The case's web page is:

http://www.codegen.com.tr/desktop/ms-2.htm

We have the MS2-G7, which is the same as the MS2-G10 except for the color.
Some translation for the Turkish terms on that page (not that you wouldn't
be able to figure it out): "Boyutlar" means "Dimensions", "Surucu Yuvalari"
means "Drive Bays" and "Ses & Mikrofon" means "Sound and Microphone"

The actual dimensions of the PSU, if relevant, are 45mm x 80mm x 220mm (1.8"
x 3.2" x 8.8") (WxHxD), and it has two 4cm (1.6") fans, one one each end.

Here we have 220V/50Hz mains.

Pentium-M is hard to find here and importing from outside Turkey has too
much paperwork and extra costs attached. Of course, another case could be an
option, but strangely, this brand is the only one supplying these "slim"
ones and portability is also a factor.

Now, assuming that the information on the label's picture will not bring any
good news (but hoping for the opposite), should ve resort to plain AthlonXPs
and older P4s? For example, AMD documentation
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26237.PDF
states that an AthlonXP 2800+ draws a max. of 68.3W, which is just slightly
above the 65Watts that can be drawn (according to its label) from the +5V
line of this PSU. Similar options may be available for the P4 family too...

When is the "Max" power needed? When the CPU is running at 100% capacity
according to Windows Task Manager, is it also drawing the max. current /
power from the PSU? Is the duration a factor here?

Many thanks *again*,
Best,
-arifi

You want to design a computer with no compromises. That means it
should be able to run 24 hours a day with the Windows Task Manager
at 100%, without the power supply being stressed or without
the computer overheating. That means the power supply must have
adequate power and the computer must have an adequate cooling system.
(You wouldn't want the system to quit right in the middle of your
demonstration to customers.)

You have picked a very challenging system build. To build a small
system, means either using the best technology available, or
you have to accept a lower performance level.

Here is an example. I think this system is roughly the same
size as your computer case. This is an Asus barebones system,
with computer case, power supply, motherboard being the bare
essentials.

http://usa.asus.com/prog/spec.asp?langs=09&m=Prodigy P4S

Notice how the computer takes PC2100 ram and up to 2.5GHz
processor. The size of the box and the capacity of the
power supply limit what you can do.

Since you are familiar with Asus, perhaps you should look
through the barebones systems, for one that is acceptable.

***********
A more expensive option, is a Shuttle. It is (L)300*(W)200*(H)185.
dimensions. It has a 250W power supply. The power supply specs are here:
http://www.extremeoverclocking.com/reviews/systems/images/Shuttle_SB75G2/Shuttle_Case_PSU.jpg

There is a review here.
http://www.extremeoverclocking.com/reviews/systems/Shuttle_SB75G2_1.html

The Shuttle web site is here. The SB75G2 is equivalent to a P4C800
Asus motherboard, roughly speaking. But only two DIMM slots.
http://global.shuttle.com/Product/Barebone/brb_default.asp

This support page claims the case can take a P4 3.4GHz and
a 9800XT video card. The case has a heat pipe cooling system,
for moving processor heat to a fan on the back of the computer.
http://global.shuttle.com/Support/SupportList.asp?Item=SB75G2

This product is expensive, and when I was investigating building
a system for a relative with this product, the total price for the
system was becoming astronomical.

As you can see from the power output on the power supply:
3.3V@18A 5V@19A 12V@16A [email protected]

the power in the Shuttle case is sufficient for a decent P4
system.
***********

You can fix the power problem, by searching for a 1U power supply.
This page has a couple of examples. This company has a reputation
for producing the Cadillac of power supplies, so they are
expensive ($99 US) but worth it. This one is 3.95"W x 7.9"D x 1.6"H,
so it is a bit wider than your current power supply, but has
much better numbers:

http://www.pcpowerandcooling.com/products/power_supplies/highperformance/turbocools/index_hp_1u.htm
+3.3V@20A 5V@30A +12V@16A +5VSB@2A [email protected]

With this, you could build an AMD or an Intel system.

But, once all that heat is inside your computer case, would there
be enough fans to remove the heat ?
***********

Now, what can you build with your existing power ?
+3.3@7A +5@13A +12@6A +5VSB@1A

On the AthlonXP side, I don't think you have enough +5V to run
one. The thing is, there is more than the processor drawing on
+5V, and that is what would make it tough. The 1700+ has the best
power numbers in this table:
http://groups.google.ca/[email protected]

A 2GHz Celeron FSB400 is 53W. It would use up a bit more than 4 amps
for the processor. You would need to locate the CDROM drive from a
laptop, as some of those are powered by +5V only, and you have a
bit more +5V to spare. You have many choices for hard drives, and
may be able to find something that runs from +5V (again, possibly
a laptop drive, or even a drive in a USB enclosure might do the
trick).

Here are the Celeron specs:
http://processorfinder.intel.com/scripts/details.asp?sSpec=sl6vr

Now, looking at my notes, the P4C800-E seems to draw too much from
+3.3V to work with your power supply. Even if using only one stick
of RAM (the memory is powered by +3.3V on that board). There might
be other motherboards that power the RAM from +5V. So, the motherboard
choice would be tricky, to make the 2Ghz Celeron work out. You would
have a hard time determining just how much +5 and +3.3V comsumption
you've got.

The Via Nehemiah processor (1.4GHz 21W power) might be a possibility.
http://www.mini-itx.com is a website dedicated to small computing
products, and they have a store as well. Probably not enough computing
power for what you want. Various designs using 60, 90, or 120W
power supplies. They have a P4 mini-itx motherboard there, but
since it doesn't give details of its power requirements, it might
not work with your +3.3V@7A limit.

If I were in your shoes, I would toss that computer case and
power supply in the back closet, then go shopping for a barebones
system.

Put a Northwood 2.8C/FSB800/512KB processor in this barebones system.
The only thing I don't like about this, is it uses an ATI chipset.
Power supply = +3.3@8A +5@4A [email protected] [email protected] [email protected]
Not a lot more than your current supply, but the +12V is a bit better.

http://usa.asus.com/products/desktop/pundit-r/overview.htm

The Pundit-R must be running the DIMMs off of the +3.3V supply.
The +5V@4A would be used mainly for your disk drives. That would
be enough for a simple CDROM and a hard drive. (Note - in this case,
you do not want to buy or use laptop components, as you don't have
enough +5V for them, ordinary drives using +5 and +12 are the
right answer.) The +12V is enough for the 6.45A of the 2.8Ghz
Northwood, leaving 3 amps to run the hard drive and CDROM.

If you download the manual:
ftp://ftp.asus.com.tw/pub/ASUS/Barebone/Pundit/manual/e1611_ab-p2800_pundit-r.pdf

the BIOS has the silly "DRAM CAS Select" [Fast,Slow]. You may have
to try a couple of different DIMMs until you find something that
works well with this board. The board supports dual channel RAM
operation.

The Pundit-R has no AGP slot, so if you really don't like the
built-in graphics, the only option you would have, is to find
a PCI graphics card (and you'd probably run out of +5V power if
you try that). The small size of this system is partially
responsible for the design tradeoffs. Some other barebones
systems do offer AGP, but have other compromises (case doesn't
look as nice). Check Google for comments about this product.

Anyway, I spent a month about a year ago, researching some of
these possibilities, and I ended up just throwing in the towel
and buying one similar to this. This unit has a power supply in
the base, and when running at 100% in the task manager with
a 2.8Ghz processor, the fan makes a lot of noise. And this
wasn't cheap either. It has a 1280x1024 LCD display and a
compact footprint.

http://www.clevo.com.tw/products/L297U.asp

I also liked the look of this, but couldn't locate a retailer
willing to sell one. This is basically a laptop, but without
the LCD, and it has a VGA output. I think it may have already
been discontinued:

http://web.archive.org/web/20040213015122/http://www.ecs.com.tw/products/a980.htm

P.S. In my two sample home systems that I measured, the power
figures I gave are for just the motherboard. I neglected to measure
the hard drive and CDROM drive, so they aren't included.

I hope you have a large budget for this project. It helps

Have fun,
Paul

 

[Arifi Koseoglu]

Dear Paul,

The web site of the company producing (actually, importing from China)
the
case does not have any details on the PSU, so I removed the PSU from the
case, scanned the three sides on which the label was wrapped, combined
the
three images and put the file on our web site:

http://www.mind2biz.com/download/codegen_psu_label.jpg

The case's web page is:

http://www.codegen.com.tr/desktop/ms-2.htm

We have the MS2-G7, which is the same as the MS2-G10 except for the
color.
Some translation for the Turkish terms on that page (not that you
wouldn't
be able to figure it out): "Boyutlar" means "Dimensions", "Surucu
Yuvalari"
means "Drive Bays" and "Ses & Mikrofon" means "Sound and Microphone"

The actual dimensions of the PSU, if relevant, are 45mm x 80mm x 220mm
(1.8"
x 3.2" x 8.8") (WxHxD), and it has two 4cm (1.6") fans, one one each end.

Here we have 220V/50Hz mains.

Pentium-M is hard to find here and importing from outside Turkey has too
much paperwork and extra costs attached. Of course, another case could be
an
option, but strangely, this brand is the only one supplying these "slim"
ones and portability is also a factor.

Now, assuming that the information on the label's picture will not bring
any
good news (but hoping for the opposite), should ve resort to plain
AthlonXPs
and older P4s? For example, AMD documentation
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26237.PDF
states that an AthlonXP 2800+ draws a max. of 68.3W, which is just
slightly
above the 65Watts that can be drawn (according to its label) from the +5V
line of this PSU. Similar options may be available for the P4 family
too...

When is the "Max" power needed? When the CPU is running at 100% capacity
according to Windows Task Manager, is it also drawing the max. current /
power from the PSU? Is the duration a factor here?

Many thanks *again*,
Best,
-arifi

You want to design a computer with no compromises. That means it
should be able to run 24 hours a day with the Windows Task Manager
at 100%, without the power supply being stressed or without
the computer overheating. That means the power supply must have
adequate power and the computer must have an adequate cooling system.
(You wouldn't want the system to quit right in the middle of your
demonstration to customers.)

You have picked a very challenging system build. To build a small
system, means either using the best technology available, or
you have to accept a lower performance level.

Here is an example. I think this system is roughly the same
size as your computer case. This is an Asus barebones system,
with computer case, power supply, motherboard being the bare
essentials.

http://usa.asus.com/prog/spec.asp?langs=09&m=Prodigy P4S

Notice how the computer takes PC2100 ram and up to 2.5GHz
processor. The size of the box and the capacity of the
power supply limit what you can do.

Since you are familiar with Asus, perhaps you should look
through the barebones systems, for one that is acceptable.

***********
A more expensive option, is a Shuttle. It is (L)300*(W)200*(H)185.
dimensions. It has a 250W power supply. The power supply specs are here:
http://www.extremeoverclocking.com/reviews/systems/images/Shuttle_SB75G2/Shuttle_Case_PSU.jpg

There is a review here.
http://www.extremeoverclocking.com/reviews/systems/Shuttle_SB75G2_1.html

The Shuttle web site is here. The SB75G2 is equivalent to a P4C800
Asus motherboard, roughly speaking. But only two DIMM slots.
http://global.shuttle.com/Product/Barebone/brb_default.asp

This support page claims the case can take a P4 3.4GHz and
a 9800XT video card. The case has a heat pipe cooling system,
for moving processor heat to a fan on the back of the computer.
http://global.shuttle.com/Support/SupportList.asp?Item=SB75G2

This product is expensive, and when I was investigating building
a system for a relative with this product, the total price for the
system was becoming astronomical.

As you can see from the power output on the power supply:
3.3V@18A 5V@19A 12V@16A [email protected]

the power in the Shuttle case is sufficient for a decent P4
system.
***********

You can fix the power problem, by searching for a 1U power supply.
This page has a couple of examples. This company has a reputation
for producing the Cadillac of power supplies, so they are
expensive ($99 US) but worth it. This one is 3.95"W x 7.9"D x 1.6"H,
so it is a bit wider than your current power supply, but has
much better numbers:

http://www.pcpowerandcooling.com/products/power_supplies/highperformance/turbocools/index_hp_1u.htm
+3.3V@20A 5V@30A +12V@16A +5VSB@2A [email protected]

With this, you could build an AMD or an Intel system.

But, once all that heat is inside your computer case, would there
be enough fans to remove the heat ?
***********

Now, what can you build with your existing power ?
+3.3@7A +5@13A +12@6A +5VSB@1A

On the AthlonXP side, I don't think you have enough +5V to run
one. The thing is, there is more than the processor drawing on
+5V, and that is what would make it tough. The 1700+ has the best
power numbers in this table:
http://groups.google.ca/[email protected]

A 2GHz Celeron FSB400 is 53W. It would use up a bit more than 4 amps
for the processor. You would need to locate the CDROM drive from a
laptop, as some of those are powered by +5V only, and you have a
bit more +5V to spare. You have many choices for hard drives, and
may be able to find something that runs from +5V (again, possibly
a laptop drive, or even a drive in a USB enclosure might do the
trick).

Here are the Celeron specs:
http://processorfinder.intel.com/scripts/details.asp?sSpec=sl6vr

Now, looking at my notes, the P4C800-E seems to draw too much from
+3.3V to work with your power supply. Even if using only one stick
of RAM (the memory is powered by +3.3V on that board). There might
be other motherboards that power the RAM from +5V. So, the motherboard
choice would be tricky, to make the 2Ghz Celeron work out. You would
have a hard time determining just how much +5 and +3.3V comsumption
you've got.

The Via Nehemiah processor (1.4GHz 21W power) might be a possibility.
http://www.mini-itx.com is a website dedicated to small computing
products, and they have a store as well. Probably not enough computing
power for what you want. Various designs using 60, 90, or 120W
power supplies. They have a P4 mini-itx motherboard there, but
since it doesn't give details of its power requirements, it might
not work with your +3.3V@7A limit.

If I were in your shoes, I would toss that computer case and
power supply in the back closet, then go shopping for a barebones
system.

Put a Northwood 2.8C/FSB800/512KB processor in this barebones system.
The only thing I don't like about this, is it uses an ATI chipset.
Power supply = +3.3@8A +5@4A [email protected] [email protected] [email protected]
Not a lot more than your current supply, but the +12V is a bit better.

http://usa.asus.com/products/desktop/pundit-r/overview.htm

The Pundit-R must be running the DIMMs off of the +3.3V supply.
The +5V@4A would be used mainly for your disk drives. That would
be enough for a simple CDROM and a hard drive. (Note - in this case,
you do not want to buy or use laptop components, as you don't have
enough +5V for them, ordinary drives using +5 and +12 are the
right answer.) The +12V is enough for the 6.45A of the 2.8Ghz
Northwood, leaving 3 amps to run the hard drive and CDROM.

If you download the manual:
ftp://ftp.asus.com.tw/pub/ASUS/Barebone/Pundit/manual/e1611_ab-p2800_pundit-r.pdf

the BIOS has the silly "DRAM CAS Select" [Fast,Slow]. You may have
to try a couple of different DIMMs until you find something that
works well with this board. The board supports dual channel RAM
operation.

The Pundit-R has no AGP slot, so if you really don't like the
built-in graphics, the only option you would have, is to find
a PCI graphics card (and you'd probably run out of +5V power if
you try that). The small size of this system is partially
responsible for the design tradeoffs. Some other barebones
systems do offer AGP, but have other compromises (case doesn't
look as nice). Check Google for comments about this product.

Anyway, I spent a month about a year ago, researching some of
these possibilities, and I ended up just throwing in the towel
and buying one similar to this. This unit has a power supply in
the base, and when running at 100% in the task manager with
a 2.8Ghz processor, the fan makes a lot of noise. And this
wasn't cheap either. It has a 1280x1024 LCD display and a
compact footprint.

http://www.clevo.com.tw/products/L297U.asp

I also liked the look of this, but couldn't locate a retailer
willing to sell one. This is basically a laptop, but without
the LCD, and it has a VGA output. I think it may have already
been discontinued:

http://web.archive.org/web/20040213015122/http://www.ecs.com.tw/products/a980.htm

P.S. In my two sample home systems that I measured, the power
figures I gave are for just the motherboard. I neglected to measure
the hard drive and CDROM drive, so they aren't included.

I hope you have a large budget for this project. It helps

Have fun,
Paul

Dear Paul,

Following your suggestion, we have looked into the barebones and Shuttle
family. They are to be found here, and may resort to them eventually.

Before that, however, I have tried to locate a decent 1U PSU here, was able
to find one that seemed ok on only one company's web site, but it turned out
that the company had moved w/o a trace - no response to my e-mail query
either. It seems that people here are only selling main-stream PSUs, (but
some with neon lighting !! ) ). The other option remaining is server spare
parts, which are special order too (also expensive).

Then I started looking into specs of AMD cpus again. This time Semprons,
settling for less performance. To my surprise, there exists one that has a
Barton core with 512K L2: the Sempron 3000+ (Socket A). I assumed this
cannot perform worse that an AthlonXP; and has a TDP of only 62Watts !!. I
decided to give it a try. Worse comes worst, we will use it in one of our
other desktop systems.

Having the Sempron, and a previously purchased SATA drive at hand, finding
the MoBo became an issue, since none of the microATX all-in-one Asus' being
sold here support SATA (iow neither the A7S8X-MX nore the A7V400-MX-SE is to
find). Same applies to Gigabyte, so I had to settle for an MSI KM4M-V (VIA
KM400A).

The first test will be to see how the MSI + Sempron run on the crappy PSU
that came with the box. We will then look into the other options as
necessary.

I thank you again for your time and all the detailed valuable information
you have provided.

Best,
-arifi

 

[Arifi Koseoglu]

Dear Paul,

The web site of the company producing (actually, importing from China)
the
case does not have any details on the PSU, so I removed the PSU from the
case, scanned the three sides on which the label was wrapped, combined
the
three images and put the file on our web site:

http://www.mind2biz.com/download/codegen_psu_label.jpg

The case's web page is:

http://www.codegen.com.tr/desktop/ms-2.htm

We have the MS2-G7, which is the same as the MS2-G10 except for the
color.
Some translation for the Turkish terms on that page (not that you
wouldn't
be able to figure it out): "Boyutlar" means "Dimensions", "Surucu
Yuvalari"
means "Drive Bays" and "Ses & Mikrofon" means "Sound and Microphone"

The actual dimensions of the PSU, if relevant, are 45mm x 80mm x 220mm
(1.8"
x 3.2" x 8.8") (WxHxD), and it has two 4cm (1.6") fans, one one each
end.

Here we have 220V/50Hz mains.

Pentium-M is hard to find here and importing from outside Turkey has too
much paperwork and extra costs attached. Of course, another case could
be an
option, but strangely, this brand is the only one supplying these "slim"
ones and portability is also a factor.

Now, assuming that the information on the label's picture will not bring
any
good news (but hoping for the opposite), should ve resort to plain
AthlonXPs
and older P4s? For example, AMD documentation
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/26237.PDF
states that an AthlonXP 2800+ draws a max. of 68.3W, which is just
slightly
above the 65Watts that can be drawn (according to its label) from the
+5V
line of this PSU. Similar options may be available for the P4 family
too...

When is the "Max" power needed? When the CPU is running at 100% capacity
according to Windows Task Manager, is it also drawing the max. current /
power from the PSU? Is the duration a factor here?

Many thanks *again*,
Best,
-arifi

You want to design a computer with no compromises. That means it
should be able to run 24 hours a day with the Windows Task Manager
at 100%, without the power supply being stressed or without
the computer overheating. That means the power supply must have
adequate power and the computer must have an adequate cooling system.
(You wouldn't want the system to quit right in the middle of your
demonstration to customers.)

You have picked a very challenging system build. To build a small
system, means either using the best technology available, or
you have to accept a lower performance level.

Here is an example. I think this system is roughly the same
size as your computer case. This is an Asus barebones system,
with computer case, power supply, motherboard being the bare
essentials.

http://usa.asus.com/prog/spec.asp?langs=09&m=Prodigy P4S

Notice how the computer takes PC2100 ram and up to 2.5GHz
processor. The size of the box and the capacity of the
power supply limit what you can do.

Since you are familiar with Asus, perhaps you should look
through the barebones systems, for one that is acceptable.

***********
A more expensive option, is a Shuttle. It is (L)300*(W)200*(H)185.
dimensions. It has a 250W power supply. The power supply specs are here:
http://www.extremeoverclocking.com/reviews/systems/images/Shuttle_SB75G2/Shuttle_Case_PSU.jpg

There is a review here.
http://www.extremeoverclocking.com/reviews/systems/Shuttle_SB75G2_1.html

The Shuttle web site is here. The SB75G2 is equivalent to a P4C800
Asus motherboard, roughly speaking. But only two DIMM slots.
http://global.shuttle.com/Product/Barebone/brb_default.asp

This support page claims the case can take a P4 3.4GHz and
a 9800XT video card. The case has a heat pipe cooling system,
for moving processor heat to a fan on the back of the computer.
http://global.shuttle.com/Support/SupportList.asp?Item=SB75G2

This product is expensive, and when I was investigating building
a system for a relative with this product, the total price for the
system was becoming astronomical.

As you can see from the power output on the power supply:
3.3V@18A 5V@19A 12V@16A [email protected]

the power in the Shuttle case is sufficient for a decent P4
system.
***********

You can fix the power problem, by searching for a 1U power supply.
This page has a couple of examples. This company has a reputation
for producing the Cadillac of power supplies, so they are
expensive ($99 US) but worth it. This one is 3.95"W x 7.9"D x 1.6"H,
so it is a bit wider than your current power supply, but has
much better numbers:

http://www.pcpowerandcooling.com/products/power_supplies/highperformance/turbocools/index_hp_1u.htm
+3.3V@20A 5V@30A +12V@16A +5VSB@2A [email protected]

With this, you could build an AMD or an Intel system.

But, once all that heat is inside your computer case, would there
be enough fans to remove the heat ?
***********

Now, what can you build with your existing power ?
+3.3@7A +5@13A +12@6A +5VSB@1A

On the AthlonXP side, I don't think you have enough +5V to run
one. The thing is, there is more than the processor drawing on
+5V, and that is what would make it tough. The 1700+ has the best
power numbers in this table:
http://groups.google.ca/[email protected]

A 2GHz Celeron FSB400 is 53W. It would use up a bit more than 4 amps
for the processor. You would need to locate the CDROM drive from a
laptop, as some of those are powered by +5V only, and you have a
bit more +5V to spare. You have many choices for hard drives, and
may be able to find something that runs from +5V (again, possibly
a laptop drive, or even a drive in a USB enclosure might do the
trick).

Here are the Celeron specs:
http://processorfinder.intel.com/scripts/details.asp?sSpec=sl6vr

Now, looking at my notes, the P4C800-E seems to draw too much from
+3.3V to work with your power supply. Even if using only one stick
of RAM (the memory is powered by +3.3V on that board). There might
be other motherboards that power the RAM from +5V. So, the motherboard
choice would be tricky, to make the 2Ghz Celeron work out. You would
have a hard time determining just how much +5 and +3.3V comsumption
you've got.

The Via Nehemiah processor (1.4GHz 21W power) might be a possibility.
http://www.mini-itx.com is a website dedicated to small computing
products, and they have a store as well. Probably not enough computing
power for what you want. Various designs using 60, 90, or 120W
power supplies. They have a P4 mini-itx motherboard there, but
since it doesn't give details of its power requirements, it might
not work with your +3.3V@7A limit.

If I were in your shoes, I would toss that computer case and
power supply in the back closet, then go shopping for a barebones
system.

Put a Northwood 2.8C/FSB800/512KB processor in this barebones system.
The only thing I don't like about this, is it uses an ATI chipset.
Power supply = +3.3@8A +5@4A [email protected] [email protected] [email protected]
Not a lot more than your current supply, but the +12V is a bit better.

http://usa.asus.com/products/desktop/pundit-r/overview.htm

The Pundit-R must be running the DIMMs off of the +3.3V supply.
The +5V@4A would be used mainly for your disk drives. That would
be enough for a simple CDROM and a hard drive. (Note - in this case,
you do not want to buy or use laptop components, as you don't have
enough +5V for them, ordinary drives using +5 and +12 are the
right answer.) The +12V is enough for the 6.45A of the 2.8Ghz
Northwood, leaving 3 amps to run the hard drive and CDROM.

If you download the manual:
ftp://ftp.asus.com.tw/pub/ASUS/Barebone/Pundit/manual/e1611_ab-p2800_pundit-r.pdf

the BIOS has the silly "DRAM CAS Select" [Fast,Slow]. You may have
to try a couple of different DIMMs until you find something that
works well with this board. The board supports dual channel RAM
operation.

The Pundit-R has no AGP slot, so if you really don't like the
built-in graphics, the only option you would have, is to find
a PCI graphics card (and you'd probably run out of +5V power if
you try that). The small size of this system is partially
responsible for the design tradeoffs. Some other barebones
systems do offer AGP, but have other compromises (case doesn't
look as nice). Check Google for comments about this product.

Anyway, I spent a month about a year ago, researching some of
these possibilities, and I ended up just throwing in the towel
and buying one similar to this. This unit has a power supply in
the base, and when running at 100% in the task manager with
a 2.8Ghz processor, the fan makes a lot of noise. And this
wasn't cheap either. It has a 1280x1024 LCD display and a
compact footprint.

http://www.clevo.com.tw/products/L297U.asp

I also liked the look of this, but couldn't locate a retailer
willing to sell one. This is basically a laptop, but without
the LCD, and it has a VGA output. I think it may have already
been discontinued:

http://web.archive.org/web/20040213015122/http://www.ecs.com.tw/products/a980.htm

P.S. In my two sample home systems that I measured, the power
figures I gave are for just the motherboard. I neglected to measure
the hard drive and CDROM drive, so they aren't included.

I hope you have a large budget for this project. It helps

Have fun,
Paul

Dear Paul,

Following your suggestion, we have looked into the barebones and Shuttle
family. They are to be found here, and may resort to them eventually.

Before that, however, I have tried to locate a decent 1U PSU here, was
able to find one that seemed ok on only one company's web site, but it
turned out that the company had moved w/o a trace - no response to my
e-mail query either. It seems that people here are only selling
main-stream PSUs, (but some with neon lighting !! ) ). The other option
remaining is server spare parts, which are special order too (also
expensive).

Then I started looking into specs of AMD cpus again. This time Semprons,
settling for less performance. To my surprise, there exists one that has a
Barton core with 512K L2: the Sempron 3000+ (Socket A). I assumed this
cannot perform worse that an AthlonXP; and has a TDP of only 62Watts !!. I
decided to give it a try. Worse comes worst, we will use it in one of our
other desktop systems.

Having the Sempron, and a previously purchased SATA drive at hand, finding
the MoBo became an issue, since none of the microATX all-in-one Asus'
being sold here support SATA (iow neither the A7S8X-MX nore the
A7V400-MX-SE is to find). Same applies to Gigabyte, so I had to settle for
an MSI KM4M-V (VIA KM400A).

The first test will be to see how the MSI + Sempron run on the crappy PSU
that came with the box. We will then look into the other options as
necessary.

I thank you again for your time and all the detailed valuable information
you have provided.

Best,
-arifi

And of course, I also thank Rob, Ed and Lenny for their input in this
discussion.
Very much appreciated.
Cheers
-arifi

 

[Paul]

Dear Paul,

Following your suggestion, we have looked into the barebones and Shuttle
family. They are to be found here, and may resort to them eventually.

Before that, however, I have tried to locate a decent 1U PSU here, was able
to find one that seemed ok on only one company's web site, but it turned out
that the company had moved w/o a trace - no response to my e-mail query
either. It seems that people here are only selling main-stream PSUs, (but
some with neon lighting !! ) ). The other option remaining is server spare
parts, which are special order too (also expensive).

Then I started looking into specs of AMD cpus again. This time Semprons,
settling for less performance. To my surprise, there exists one that has a
Barton core with 512K L2: the Sempron 3000+ (Socket A). I assumed this
cannot perform worse that an AthlonXP; and has a TDP of only 62Watts !!. I
decided to give it a try. Worse comes worst, we will use it in one of our
other desktop systems.

Having the Sempron, and a previously purchased SATA drive at hand, finding
the MoBo became an issue, since none of the microATX all-in-one Asus' being
sold here support SATA (iow neither the A7S8X-MX nore the A7V400-MX-SE is to
find). Same applies to Gigabyte, so I had to settle for an MSI KM4M-V (VIA
KM400A).

The first test will be to see how the MSI + Sempron run on the crappy PSU
that came with the box. We will then look into the other options as
necessary.

I thank you again for your time and all the detailed valuable information
you have provided.

Best,
-arifi

I think you've made an excellent choice. The KM4M-V has a +12V 2x2
power connector. That means your processor is using +12V as its
source of power. (Asus likes to use +5V for the processor instead,
so your choice of the MSI board was a lucky one.)

(62W/12V)*(1.0/0.9)=5.74 amps from +12V. Leaves 0.26 amps for fans!

+3.3@7A +5@13A +12@6A +5VSB@1A

Based on that choice, I think that means your disk drives are
going to have to be powered by +5V. That means using parts
from a laptop perhaps (no SATA?). Depending on the parts you get,
you may need some kind of adapter, to go from 44 pins to 40 pins
for the hard drive.

******************
Here is an 80GB 2.5" 5400RPM disk drive that uses no more than
1 amp at +5V. It doesn't use any +12V. This drive has a 44 pin
connector, and I think this is the standard 40 pins plus
some kind of powering scheme. You'll need an adapter cable to
fit this into your computer, plus will need to come up with a
mounting scheme.

MK8026GAX (HDD2191) 80GB HDD
http://sdd.toshiba.com/cda/main.aspx?Path=/818200000ab6000000010000659c00002567

The adapter at the bottom of this page, will adapt from a
44 pin laptop drive connector, to a desktop IDE connector:

http://mini-itx.com/store/?c=12#p2006
******************
This CDRW/DVDROM reader uses +5V but no current is specified.
The mini-itx site has more models to choose from.

Mobile 24x24x24x8x SD-R2612
http://sdd.toshiba.com/cda/main.aspx?Path=/818200000a1c000000010000659c0000231c

This "Slimline CD to Desktop IDE" adapter can adapt a laptop
CDROM to an ordinary IDE connector plus drive power connector.

http://mini-itx.com/store/?c=5#p2112
******************

By using drives that use +5V, you avoid overloading the +12V rail.
I wouldn't try using the CD writer function, unless you've
verified how much total +5V current is being used, as reading
should use less current than attempting to write.

The only issue remaining, is whether there is enough current
left for cooling fans. For a temporary source of power, you
might want to find a separate ATX power supply, jumper PS_ON#
to COM (a.k.a GND), and then you can connect whatever fans you
want to the drive connectors on the ATX supply.

Pg.29 here shows the connector pinouts on an older ATX supply:

http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf

I really recommend measuring the current consumption of your
design, to avoid a failure right in the middle of a customer
demo. The clamp-on DC ammeter means you don't have to cut any
wires to measure the current. You can use a precision current
shunt, but that would mean cutting the wires on the ATX power
supply cable and splicing the shunt into line. And the shunts
are generally not cheap ($50 a piece, and you need one for
+3.3V, +5V, +12V). For example, the LA-15-100 develops 100mV
across it, when 15 amps is flowing through it.

http://www.cshunt.com/pdf/la.pdf

This is how you would use a shunt. Cut the four +5V wires,
and join the ends. When connected as shown, all the +5V
current to the motherboard, flows through the shunt.
By touching a voltmeter across the current shunt terminals,
you can check the voltage developed, and the current will
be directly proportional to the voltage seen. (i.e. 100mV
when there is 15 amps, using the LA-15-100 in the sample
datasheet above). If you don't want to hack up the power
supply cable, you can buy a 20pin to 20pin ATX power
extender cable, and mount the shunts on that. When you
are finished measuring the current, you can just remove
the extender 20pin cable.

----------+--current shunt--+-------------> | |
----------+ +-------------> | |
----------+ +-------------> | |
----------+ +------------->

It is too bad no one makes cheap inferior shunts - it seems
they are either precision, or they don't exist.

Here is a mobile AthlonXP. This one draws 35 watts, if you
operate it from 1.35V. To run at the low voltage, you need
a motherboard that allows setting the voltage that low.
(An Asus board won't do that. There is a utility to modify
FID/VID in Windows, that may work to do this. Check the MSI
BIOS to see if this is possible, as setting the voltage in
the BIOS is a lot easier.) So, it is possible to come up with
a lower power solution. A processor like this can be run at
3200+ processor rates, but then the power dissipation will
rise to the level of the Sempron you have purchased. Thus,
to get the rated power, you have to stick with the conditions
stated in the advert. In an emergency, you could also drop the
clock rate to the Sempron, but the advantage of the Mobile
processor listed above, is it has been tested under the listed
conditions.

http://www.newegg.com/app/ViewProductDesc.asp?description=19-103-439&depa=0

Based on the economics and implementation complexity, I
still think dumping that little power supply will cost
you a lot less time and money in the long run. A Shuttle
will cost you up front, but will not require any fiddling
to get it to work (you can use ordinary disk drives, and you
won't have to measure any currents while doing the build).
The build with the Shuttle should be no more dramatic than
building a regular desktop. As long as you don't try to stick
too much of a thermal load in it, it should work just fine.

HTH,
Paul

 

[Paul]

Something else that occurred to me - when I checked the datasheet
for the Sempron 3000+ Model 10 (effectively a Barton core), it is
62 watts max, and 49.4 watts typical, which means the real
power won't be quite as bad as I indicated in the other post.
You still cannot afford to draw hard disk/CDROM power from +12V,
but at least the power supply is not about to "fall over" due to
the processor load.

The Barton 3000+ is 74.3W max and 58.4W typical. And the reason
for the higher power, is AthlonXP compares to Pentium4, while
Sempron compares to Celeron. So, your Sempron 3000+ is comparable
to a Celeron 3000, while an AthlonXP 3000+ is comparable
to a Pentium 4 3.0GHz. The AthlonXP 3000+ draws more power,
because it is a more powerful processor than the Sempron 3000+.

Paul

 

[aberger]

Hello everyone,

At work we wish to build a small-footprint demo computer using one of
those thin (10cm / 4 inches high) desktop cases, which will be easy to
carry to customer's sites, and such. We prefer this way rather than
buying a strong laptop since we believe such a system will perform
better and be more flexible.

The case we have found has a power suply capable of producing 230
Watts, and they claim it easily drives P4 systems. The case can house
microATX size MoBos. The power supply is a thin and long one custom for
this case, so there is no easy way to upgrade the PSU.

Being primarily an ASUS house, we searched for "microatx" and "matx" on
their web site, and the following motherboards were listed:

P5GD1-VM
P4GE-MX
P4R800-VM
P4P800-VM
P4BP-MX
P4S800-MX
P4SP-MX
P4SP-MX SE
P4V533-MX
P4VP-MX
A7N8X-VM
A7N8X-VM/400
P5S800-VM
K8S-MX

I would assume all to be nice boards, but we have not been able to find
conclusive information about how much Wattage the complete system built
around one ot them would require.

The system will contain the Motherboard, 2x512MB DDR RAM, 1x P4 CPU, 1x
SATA drive, CDROM Player, cabled keyboard and cabled mouse. No other
attachments except for a monitor or a projection device. The amount of
computing power we need is at the order of a P4-2800 with 1Meg Cache,
but we do know that we will have to settle with the max. that the power
supply can drive.

There are Power Supply calculators out there, but the ones I have
looked into do not consider all-in-one boards like the ones above where
the graphics card, lan etc are all on the motherboard.

So the Question is: How can I find out how much power these
motherboards will draw? What is the strongest CPU/MoBo combination I
can use with the 230W PS we have? (he system will be run at rated
speeds - no overclocking)

I will appreciate any information and any pointers deeply.

Many thanks in advance,
-arifi

Couple of commments:

1- You can always underclock the CPU to save power.
2- Don't neglect the start-up current of the hard drive. It can be 50%
greater than the steady state current.
3- You might want to look into solid state disks using flash
technology. Less power and no moving parts. Great for throwing in the
trunk of the sales engineer's car.

arnie

 

[Arifi Koseoglu]

I think you've made an excellent choice. The KM4M-V has a +12V 2x2
power connector. That means your processor is using +12V as its
source of power. (Asus likes to use +5V for the processor instead,
so your choice of the MSI board was a lucky one.)

(62W/12V)*(1.0/0.9)=5.74 amps from +12V. Leaves 0.26 amps for fans!

+3.3@7A +5@13A +12@6A +5VSB@1A

Based on that choice, I think that means your disk drives are
going to have to be powered by +5V. That means using parts
from a laptop perhaps (no SATA?). Depending on the parts you get,
you may need some kind of adapter, to go from 44 pins to 40 pins
for the hard drive.

******************
Here is an 80GB 2.5" 5400RPM disk drive that uses no more than
1 amp at +5V. It doesn't use any +12V. This drive has a 44 pin
connector, and I think this is the standard 40 pins plus
some kind of powering scheme. You'll need an adapter cable to
fit this into your computer, plus will need to come up with a
mounting scheme.

MK8026GAX (HDD2191) 80GB HDD
http://sdd.toshiba.com/cda/main.aspx?Path=/818200000ab6000000010000659c00002567

The adapter at the bottom of this page, will adapt from a
44 pin laptop drive connector, to a desktop IDE connector:

http://mini-itx.com/store/?c=12#p2006
******************
This CDRW/DVDROM reader uses +5V but no current is specified.
The mini-itx site has more models to choose from.

Mobile 24x24x24x8x SD-R2612
http://sdd.toshiba.com/cda/main.aspx?Path=/818200000a1c000000010000659c0000231c

This "Slimline CD to Desktop IDE" adapter can adapt a laptop
CDROM to an ordinary IDE connector plus drive power connector.

http://mini-itx.com/store/?c=5#p2112
******************

By using drives that use +5V, you avoid overloading the +12V rail.
I wouldn't try using the CD writer function, unless you've
verified how much total +5V current is being used, as reading
should use less current than attempting to write.

The only issue remaining, is whether there is enough current
left for cooling fans. For a temporary source of power, you
might want to find a separate ATX power supply, jumper PS_ON#
to COM (a.k.a GND), and then you can connect whatever fans you
want to the drive connectors on the ATX supply.

Pg.29 here shows the connector pinouts on an older ATX supply:

http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf

I really recommend measuring the current consumption of your
design, to avoid a failure right in the middle of a customer
demo. The clamp-on DC ammeter means you don't have to cut any
wires to measure the current. You can use a precision current
shunt, but that would mean cutting the wires on the ATX power
supply cable and splicing the shunt into line. And the shunts
are generally not cheap ($50 a piece, and you need one for
+3.3V, +5V, +12V). For example, the LA-15-100 develops 100mV
across it, when 15 amps is flowing through it.

http://www.cshunt.com/pdf/la.pdf

This is how you would use a shunt. Cut the four +5V wires,
and join the ends. When connected as shown, all the +5V
current to the motherboard, flows through the shunt.
By touching a voltmeter across the current shunt terminals,
you can check the voltage developed, and the current will
be directly proportional to the voltage seen. (i.e. 100mV
when there is 15 amps, using the LA-15-100 in the sample
datasheet above). If you don't want to hack up the power
supply cable, you can buy a 20pin to 20pin ATX power
extender cable, and mount the shunts on that. When you
are finished measuring the current, you can just remove
the extender 20pin cable.


It is too bad no one makes cheap inferior shunts - it seems
they are either precision, or they don't exist.

Here is a mobile AthlonXP. This one draws 35 watts, if you
operate it from 1.35V. To run at the low voltage, you need
a motherboard that allows setting the voltage that low.
(An Asus board won't do that. There is a utility to modify
FID/VID in Windows, that may work to do this. Check the MSI
BIOS to see if this is possible, as setting the voltage in
the BIOS is a lot easier.) So, it is possible to come up with
a lower power solution. A processor like this can be run at
3200+ processor rates, but then the power dissipation will
rise to the level of the Sempron you have purchased. Thus,
to get the rated power, you have to stick with the conditions
stated in the advert. In an emergency, you could also drop the
clock rate to the Sempron, but the advantage of the Mobile
processor listed above, is it has been tested under the listed
conditions.

http://www.newegg.com/app/ViewProductDesc.asp?description=19-103-439&depa=0

Based on the economics and implementation complexity, I
still think dumping that little power supply will cost
you a lot less time and money in the long run. A Shuttle
will cost you up front, but will not require any fiddling
to get it to work (you can use ordinary disk drives, and you
won't have to measure any currents while doing the build).
The build with the Shuttle should be no more dramatic than
building a regular desktop. As long as you don't try to stick
too much of a thermal load in it, it should work just fine.

HTH,
Paul

Dear Paul, hello again!

First of all, many many thanks again, as usual

As you say, the shunts seem to be more exepensive probably less practical,
but it turns out that my f-i-l has a clamp-on Ammeter, and will measure the
flow once he brings it along.

The 2.5" drive suggestion is also a very good idea - but this would ramp up
the cost - a Seagate 80G 5400RPM sells for 140 USD here - probably would
rather go directly to shuttle.

As soon as I can find a better 1U PSU, I am going to drop this one, but
yesterday night I gave the system a "blind" try.

Configuration:
1. Crappy PSU ( +3.3@7A +5@13A +12@6A +5VSB@1A)
2. MSI KM4AM-V with FSB set to 166 MHz
3. Sempron 3000+ running at rated speed.
4. Seagate 80G Sata drive ([email protected] [email protected])
5. LG 48X CDROM Player (+5V@1A [email protected])
6. 1.44 Floppy (?@? ?@?) (needed to load SATA drivers during OS
installation - and later for memory diagnostics)

The MoBo does not have any voltage or fsb control in the BIOS, and provides
jumpers to set the FSB to 100, 133, 166 or 200 only.

The system booted, was able to boot from the CD to install OS (W2KSRV). Once
the
OS was installed, I removed the CDROM.

The PSU was getting pretty warm during OS installation.

The BIOS reports the voltage values as follows (the least significant digit
changes in time):

VCORE = 1.53
+3.3V = 3.10
+5V = 5.18
+12V = 11.61
-12V = -12.28
-5V = -5.09
5VSP = 4.93

MSI's monitoring software reports +12V as 11.46 in Windows, other '+' values
are reported almost the same.

W2K SP4 installed w/o problems, and the PC idled w/o problems for > 1hr.

Then I ran Microsoft Memory Diagnostics (a scaled-down Memtest86). And, I
got several errors on my Kingmax 512MB DDR400 memory sticks. I have no prior
test results for them, except for the fact that they constituted half of the
2Gigs I have on my own desktop which never crashed since its first day (for
over 4 months now - nock on the wood). I will have to install a floppy drive
and do the same test on my PC too (no CDROM since the Intel MoBo will not
allow more than 4 ATA devices - and I have 4 disks).

Is there a possibility that the PSU bottleneck is causing the memory
problems?

Today I will "push" the system by compressing large files. That should get
the HDD and CPU loaded at the same time.

Will post again with observations later.

Best,
-arifi

 

[Arifi Koseoglu]

Couple of commments:

1- You can always underclock the CPU to save power.
2- Don't neglect the start-up current of the hard drive. It can be 50%
greater than the steady state current.
3- You might want to look into solid state disks using flash
technology. Less power and no moving parts. Great for throwing in the
trunk of the sales engineer's car.

arnie

Hello Arnie,

I will end up underclocking the CPU probably, if I cannot get a proper PSU
and problems arise, but performance is also a factor - not a happy
alternative.

I do not know much (actually anything) about solid state disks - but would
assume they would cost much more than standard ones. How are
capacity/performance characteristics ?

Thanks,
-arifi