Q-fan settings and buying a variable speed detectable and variable fan: WTF

  • Thread starter Thread starter kgs
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kgs

I just bought an Asus P4C800-E deluxe, but don't have a cpu or ram yet. So:

I need to buy a fan with 3-wire; I've got a couple 2-wire already.

A 2-wire type fan has power supplied only, and the power is connected not to
the mobo, but via a molex connector to the wires that come directly from
the power supply, on the same power chain that powers the CD/HD/Floppy. If
you have a connector for CHA_FAN on the mobo it is probably a 3-wire
type,which allows mionitoring of the fans speed as well as supplying the
power, all on the same 3-pin plug, at the mobo.

I am going to try to get to the bottom of the fan speed monitoring problem
with respect to variable speed fan type options. They are cheap. For
instance,
Vantec has an 80mm that has the following specs: 23.8-41.6 cfm,
25.5-37.5dBA, 1950-3400 RPM.

These are the things you have to look for
because Asus has alluded to Q-fan as " The Asus Q-fan technology smartly
adjusts the fan speeds according to the system loading to ensure quiet, cool
and efficient operation".

I don't know if this is just alarm/ set it yourself, etc...
Probably hocus pocus. There is nothing on the web site I can find. I could
read it a thousand times and not know the first thing about what they're
talking about. Anybody got any info about this?

Are all fans adjustable? i.e. just change the power supplied and that
changes the speed. Are the resulting speeds always determinable? Do you
need a special variable adjustable, and variable monitorable fan type? In
theory I assume that at least all of the fans I will discuss here are in
fact monitorable using pcProbe, or whatever it is called now, whether in
bios, or the os, or both.

If the problem arises, how does a layman determine the correct heat setting
to use, e.g. Intel site? Anybody got any pointers. e.g H65C, M55C, L35C.
How do you get the specific information to apply to your specific processor.
Especially 2.4C, 2.6C, or 2.8C(don't know yet): are all similarly oc'able?


This could mean many things: when the computer shuts down, when the alarm
goes off, when the fan comes on, when the fan goes off, the minimum
allowable fan setting, the maximum fan speed setting, or any countless
combination... I can think of a similar number of good reasons for having
this technology.

I think the ideal possiblity is, since the mobo has cpu and mobo temp sensor
settings, and obviously (some?)fan speeds are adjustable, that you use the
feature settings this is designed for to set the max allowable temp that you
want to allow, before (i) the fan speeds up, or turns on, (ii) the settings
causing the excess heat are changed, (iii) a warning is given, (iv) the
computer shuts down... You see I'm back to the beginning again.

The bios options under Power for Q-Fan are enable/disable
When enabled select Fan Spped Ratio; any one of: 11/16 12/16 13/16 14/16
15/16. 11/16 is the minimum fan speed ratio. Select a higher ratio if you
installed additional devices and the system requires more ventilation.

Can someone who knows please clear this up


BTW, the POWMAX LP-8800C 350W ATX psu I have says on the box "supports fan
speed monitoring". Other than the connections for the disk drives, it only
has a 4-pin and 20-pin connector, which I think would be standard for this
type anyways. Will I get a power supply fan speed with this? Does the
signal come through the 20- or 4- pin connection. Alternatively, there is
also a 3-pin PWR_FAN, as well as the CHA_FAN and CPU_FAN. The CHS and PWR
fans obvoiously get the job done of determining their fan speeds through
these 3-pin connectors, which also supply the power to the fans. Is it
possible that this would connect into the psu's fan. If this is the case,
could I have this option, and what would I have to do to enable it. What
were they talking about when they said "supports fan speed monitoring"?
 
kgs said:
I just bought an Asus P4C800-E deluxe, but don't have a cpu or ram yet. So:

I need to buy a fan with 3-wire; I've got a couple 2-wire already.
Click to expand...

There are very few problems with properly mounted fans, regardless of
their location. In all of our recent installations, the heatsink/fan
that is supplied with the retail Intel P4 CPU's have done quite well,
although a little noisy, depending on the computer case. These Intel
fans are 3-wire, the third wire is the tachometer lead, but also have
their own thermal control. Consequently, the Q-Fan setting is disabled
with these fans. It is Winter in Southern California but the CPU's run
between 25 to 35 deg. C. under normal load at around 2,900 RPM.

We have also played with the ThermalTake P4 Xaser heatsink/fans under
normal speed and variable speed control. Normal speed is high and loud
but same temperatures are achieved at around 3,100 RPM.

Bottom line is that Q-Fan is effective mainly for high-RPM HSF's that
do not have its own thermal control...just to minimize the noise as
the HSF's tend to be effective in a well-ventilated case. A good CPU
temp for a P4 CPU can range from 25 to 50 deg C., depending on the
load conditions. And optimum fan speed for HSF's with manual controllers
is whatever obtains minimal fan noise at acceptable operating temp.

As for the other motherboard fan leads, there is no speed control for
fans connected to PWR or CHA. The third pin is for the tachometer.
And the PSU fan is normally independent of the motherboard.
 
Mistoffolees said:
There are very few problems with properly mounted fans, regardless of
their location. In all of our recent installations, the heatsink/fan
that is supplied with the retail Intel P4 CPU's have done quite well,
although a little noisy, depending on the computer case. These Intel
fans are 3-wire, the third wire is the tachometer lead, but also have
their own thermal control. Consequently, the Q-Fan setting is disabled
with these fans. It is Winter in Southern California but the CPU's run
between 25 to 35 deg. C. under normal load at around 2,900 RPM.

We have also played with the ThermalTake P4 Xaser heatsink/fans under
normal speed and variable speed control. Normal speed is high and loud
but same temperatures are achieved at around 3,100 RPM.

Bottom line is that Q-Fan is effective mainly for high-RPM HSF's that
do not have its own thermal control...just to minimize the noise as
the HSF's tend to be effective in a well-ventilated case. A good CPU
temp for a P4 CPU can range from 25 to 50 deg C., depending on the
load conditions. And optimum fan speed for HSF's with manual controllers
is whatever obtains minimal fan noise at acceptable operating temp.

As for the other motherboard fan leads, there is no speed control for
fans connected to PWR or CHA. The third pin is for the tachometer.
And the PSU fan is normally independent of the motherboard.
Click to expand...

It is hard to tell from the photo of the motherboard in the manual,
but the board could be using a Winbond W83627THF SuperI/O chip, which
includes a hardware monitor. The datasheet I have was downloaded from:

http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/627thf.pdf

On page 115, it says this chip only has PWM fan control outputs for
up to two fans, so three motherboard fans cannot be controlled
independently. Also, this chip is a "dumb" fan controller, in that
software has to update the "duty cycle" setting every time the fan speed
needs to be adjusted. Maybe this is done by the BIOS code - I have
no way of knowing that for sure. It is also difficult to guess at
what the control algorithm would be in the BIOS. The BIOS has the
ability to monitor some temperatures, and based on this the BIOS could
adjust the duty cycle - the BIOS could even monitor the fan RPMs recorded
by the Winbond chip, and adjust the duty cycle to achieve a fixed fan
speed at a given motherboard temperature. To know more, I would have to
connect a meter to the fan voltage and watch what happens when the processor
heats up.

Note that when using the retail Intel HSF provided with your processor,
the Intel fan also has a temperature control feature. There is a thermistor
on the Intel HSF that measures air temperature. The thermistor is monitored
by a control circuit inside the Intel fan, and the voltage to the fan
is adjusted based on the ambient temp in the case.

With the two control features enabled, sometimes you can get extreme swings
in fan speed, such as the inability to get a good maximum fan speed when
the processor is running hot. To fix this, you could either buy a CPU fan
that doesn't monitor the air temperature, you could short out the thermistor
on the Intel fan to get it to run at higher speed, or you could disable
Q-fan and rely on the Intel HSF thermistor to make the necessary adjustment.

Because a fan without the tachometer output is a few cents cheaper to make,
the market is flooded with two wire fans. This is unfortunate, as if all the
fans had tacho output, you wouldn't have to do a lot of searching to find
a good fan with RPM monitor.

The original posters questions:
Fan speed changes in proportion to voltage. Many fans are guaranteed to
spin between 7 volts and 12 volts supplied. Since the fan speed changes
in relation to the resistance to air flow, the speed is not regulated and
there can be large variations from unit to unit. To regulate the fan speed,
there are regulator chips (Maxim makes one) that watch the tachometer
output and adjust the voltage to achieve a constant speed - I've only
seen one product that uses a chip like that. Fans don't list this voltage
versus speed thing as a feature as such, but motherboards or other devices
vary the voltage to the fan, if a noise control feature is desired. As
the original poster noted, not all fans have the tacho output, so neither
hardware nor software closed loop control of speed is possible with a dumb
two pin fan.

Fan voltage can be adjusted via a variable resistor (many drive bay
controllers do that) or a variable voltage can be achieved by using
pulse width modulation (PWM) and a capacitor as an integrator. The PWM
method is efficient and doesn't heat up the transistor used to switch
the current appreciably - this is why PWM is used on a motherboard, to
avoid yet another source of heat. Since the transistor is small, there
is usually a limit to the current that can be controlled via PWM -
exceeding the current limit burns out the transistor and leaves you with
a dead fan header.

HTH,
Paul
 
"As for the other motherboard fan leads, there is no speed control for
fans connected to PWR or CHA. The third pin is for the tachometer.
And the PSU fan is normally independent of the motherboard."

On the p4c800-e dlx there are 3-pin power & monitoring connectors for
cpu/cha & pwr fans.

There is also a thermal thermal sensor cable to conect to the psu.

The key word here I guess is CONTROL. I have yet to discover if there is a
control for the cpu fan. Is this in fact true, and is this adjusted by the
asus BIOS and/or software?

My psu box POWMAX LP-8800C says "supports fan speed monitoring" ! Does this
mean it allows others to achieve this?

So for case fan options, now that I am about to buy, and everything is
riding on this as of now, to connect to the mobo CHA_FAN all I need is a
3-wire fan and that will allow tach monitoring, but no control, which is not
not an option w/ asus bios, or o/ s/w with anything other than the CPU_FAN
for the purpose o running a cool and quiet pc. All I need to find out is
what bios, or o/ s/w does exactly. These fans are pretty cheap even in red.

I'll need to figure out what this means:
I want to know what monitoring
is done by asus, and what the result is when selecting a different fan.
Fans have differnt cfms/rpms/dBAs/VAs, and POSSIBLY the ability to monitor
and change these values. One fan will not behave the same as another. p2-27
of the p2c800-e deluxe manual says the "3-pin CPU_FAN, PWR_FAN, CHA_FAN fan
connectors support cooling fans of 350mA~740mA (8.88Wmax.) or a total of
1A~2.22A (26.64W max.) at +12V". I don't know if is the variable
output(controllable range), or if any value in between is the max fan rating
to connect, and if it makes a diffrence if the fan types allows supports
monitoring and adjustment, or if all 3-wire fans do all of the above. What
about adding other built-in fan functionality inline with the 3-pin at the
mobo. I want cool, but I don't neccesarily want to bypass an already
existing technology, especially since I am ignorant as to the cause and
effects, and needs. What about attaching a reostat & tach inline on the
CHA_FAN jack on the mobo.

Can you split the fan load at the CHA-FAN connector, (and monitor) for (i)
output fan @ rear top, and (ii) input fan @ front (don't get me started
about HD cooling in the process).

I'm just upgrading to this mobo and soon will get el4200 ram, and a 2.4C-~3C
processor, and will probably want to see what it can do, in comparison to
published results. Don't know what heat to expect.
 
Theoretically you could get a seperate temperature sensor to connect b/t the
mobo and a placement in the hottest part of the psu (the highest number is
probably the one you want). This value may enter the ASUS equation.

But in order to respond to the mobo/cpu/psu temp readings by controlling the
CHA, PWR, and OTHER.... fans, (apparently the cpu fans are monitored and
adjusted based on the equation), you need to disconnect the fans from the
the mobo. If you disconnect them then you have no assurance then are
running, and you don't know their speed. If they were plugged into the
mobo, and the speed monitoring option was on, an alarm beeps, and flashes,
and you see speed 0, where normally you would be ok.
 
Unless you can control the speed inline (how about one of the many
faceplates). Can you then still have your speed read monitored by
bios/software, and have your alarm if threshold rotaion monitored this way?

At this point I'm going to need 476 componentsm, in place of an answer.
 
These things come with temp sensors for each of, say, 4 fan speed control
knobs. Sometimes the temp sensor is in the fan itself. Don't know if it
must be for this to work. Could you get a unit with individual temp sensors
that are not part of the fan, and could I use one of these to connect to
psu. This would't be advantageous in the equation, but at least I'd know
the temp. And I could get a bunch of other fans and put them all over the
pc. My psu has over temp and over power safeguards. Good thing b/c I
wouldn't know how hot to set my sensor before it e-mails the CIA.

BTW, if using a dual channel kit of EL4200 RAM with an ASUS P4C800-E
deluxe, and using the (not add~$300.00) 2.4C/2.6C/2.8C/3.0C cpu, for example
@1:1 @~280/560/1160FSB @3-3-4-7 @2.85V (w/ appropraite voltages and timings
supplied by anandtech.com) considered the best, as many sites say it is, is
this not considered overclocking, if it is indeed the best (don't try to get
better), and does that not indicate that it is going to get hot, to the
point that I may be prepared to need extra cooling.

Another site with similar results w/ma obo and ram, which may be better for
me, for cooling, for a change are at ...

fyi, I needed to find out about these fan thingies anyways.
 
winbond.com, no legitreviews.com

I have read all the reviews, and I'm gonna copy-cat as much as possible,
because there is a known means to an end. I will be preparing to tackle
any cooling issues if req'd at any time. I have 2 questions: (1)How much do
I
need for my specific purpose, and if you can (2), should I get the
specific processor.

I am upgrading because here in Toronto, using Rogers hi-speed cable
internet, I have recently discovered the newsgroups. These contain upwards
of 10, 000, 30,000, 100,000 messages in each group. I get a six pack
dispered throughout about eleven groups each day. I mark for download, and
then finally
combine and decode them, currently using OE. My old 192 MB, cusl2-c w/
eleron600(I know ) just crashes, hangs, waits, etc.. to excess.

Q1

How much EL4200 does a serious homegrown OE nntp user need: (2x256), or
(2x512)? I don't have the chance to play around. I can only do things once
at a time.

I am upgrading to an ASUS P4C800E-deluxe. I plan on also getting the 2.6C
box cpu, because it seems like a sweet spot, and is not the baby in the C
series. I assume the 2.4, 2.6, 2.8, and 3.0 behave the same. From reviews

I assume the 3.2 behaves somewhat differently, maybe more ocable. It is
also

lot more money. If recommended I could also get the 2.4C(~$???),
2.8C(add~$50), or 3.0C(unlikely)(add ~$150). I just tried to fill in this
2.4C(~$???) value above from a www site to get my facts all in a row, and
found the 2.4 and 2.6 similarly priced. I have read a couple times in
reviews that the 2.4C has been used and they said it was used because it
was very overclockable. I assumed this would be true similarly about any of
the C b/t 2.4C-3.0C. I also assumed the articles I was reading may be older,
and that the 2.4C was probably the sweet spot when the article was written,
and they would have achieved similar(and therefore better) with a 2.6C.

Q2

Any comments on the 2.4C vs 2.6C question.



don't worry, the best is yet to come, wait for ALL-IN Wonder post.
 
kgs said:
These things come with temp sensors for each of, say, 4 fan speed control
knobs. Sometimes the temp sensor is in the fan itself. Don't know if it
must be for this to work. Could you get a unit with individual temp sensors
that are not part of the fan, and could I use one of these to connect to
psu. This would't be advantageous in the equation, but at least I'd know
the temp. And I could get a bunch of other fans and put them all over the
pc. My psu has over temp and over power safeguards. Good thing b/c I
wouldn't know how hot to set my sensor before it e-mails the CIA.

BTW, if using a dual channel kit of EL4200 RAM with an ASUS P4C800-E
deluxe, and using the (not add~$300.00) 2.4C/2.6C/2.8C/3.0C cpu, for example
@1:1 @~280/560/1160FSB @3-3-4-7 @2.85V (w/ appropraite voltages and timings
supplied by anandtech.com) considered the best, as many sites say it is, is
this not considered overclocking, if it is indeed the best (don't try to get
better), and does that not indicate that it is going to get hot, to the
point that I may be prepared to need extra cooling.

Another site with similar results w/ma obo and ram, which may be better for
me, for cooling, for a change are at ...

fyi, I needed to find out about these fan thingies anyways.
Click to expand...
Let's slow down for a moment. We are getting into the minutiae but
not resolving some important questions. These include issues such
as the utilization of the P4C800-E motherboard, e.g., business,
home, gaming, etc.? Or the price category that is wanted, e.g., low
middle or high end? Other interesting points include what operating
system, e.g., Win9X vs. Windows 2000 vs. Windows XP or Linux? And
what is the local environment --- Central Australia, Alaska, if
you get the point.

OK. Answer these first for it will ultimately determine the type
of P4 CPU that will be needed, amount of RAM, other peripherals,
etc., all of which will have a bearing on PSU, cooling needs, case,
etc. To have an optimal system, all of these need to be factored.
Enabling or disabing Q-fan is one of the most minor questions that
is involved in assembling a P4C800-E. And whether or not the case
fans (i.e., non-CPU) are 2-wired or 3-wired is inconsequential if
one is not concerned about their rotation speeds. The important
point is to have an computer running as optimally as what can be
reasonably achieved.

And as for CPU fans, there are 3 variations: (a) Fixed speed, as
typical of most, but can be varied by the motherboard under Q-Fan;
(b) Variable speed, usually with its own thermal sensor, as with
the Intel HSF's provided with the retail, or "boxed", CPU's; and
(c) Variable speed controlled by external thermal sensor *or*
potentiometer, e.g., ThermalTake Xaser.
 
ya, and, and what does Q-fan do, to what, and why. Hardware usage in this
respect is based on hardware usage. Monitoring is monitoring. Varying is
varying. What varies. What is variable. What monitors. What is
monitorable. One thing may need varying while the other product does not.
I have not see any mention of dB meteres in cases. MAybe there should b.
What varies, and monitors when otherwise it may not be monitorable, or
variable. So see my question(s).

I am ignorant.
Ovrclocking makes heat.
You cannot overclock higher than using an ASUS P4C800-E with EL4200 Dual
channel RAM. I would love you too show me how to OC higher, and then I
would ask you again, does c make heat. Is OC'ing the reason you want to
controll heat, above what stock cooling is supplied, or not supplied.
The 2.4C to 30C are cousins. They overclock and behave similarly. I know
exactly what V and timings are possible to achieve max OC'ing.
The 3.2C is a different chip architecture, and behaves and OC's differently.
It is more OC'able, GHz for GHz
You must not have too much heat.
Components all work differently, including the integration of a decent fan.
Noise is bad.
Big or small I can connect them all.


I agree with you.
I cannot tell you exactly what I will be doing all the time.
So I don't exactly know how much cooling I'm gonna need. But I'm gonna be
hot either way. Guaranteed.
I'll go into the system later.
Duty-cycle and Q-fan are all I'm trying to work through. The selection of
fan may allow or not allow the system to work as a whole. It may or may not
work. The selection of cooling components will have a great effect on what
I assume is a good idea. Just gotta find out what the idea is.
Assume I have the ability to OC as much as anybody, and play a reallty
intense game as much as anybody, and I have determined the right connections
of all my hardware. Then the most efficient fans which run for the least
amount of time, at the lowest noise level, and can handle any heat I can
throw at it, with the least amout of human input, is the best. What, what?

I'll get to the more serious problems when I build the all in wonder post.
 
If you buy a 550W psu and only need 230W (as ASUS recommends for an average
system on p.2-28 of the manual) you are generating a lot more heat than you
need. But if the "duty-cycle" is much better, you may actually develop less
heat.
 
Shazam.
pc ics, superi/os OR
http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/627hf.pdf
pp39-70...

It looks like 3 fans can be turned on or off and the speed can be varied
according to various temp ranges.

So it looks like I'll need a 3-pin with tach output that is variably speed
controllable. Do I need a therm.... equipt fan mister?

I'd like an efficient one that is quiet, and conforms to the fan specs on
p2-27 of the manual (avail at asus.com). Possibly in red colour , not
UV, or LED. To match the SATA, and soon to be IDE and FLOPPY round red.

the "3-pin CPU_FAN, PWR_FAN, CHA_FAN fan
connectors support cooling fans of 350mA~740mA (8.88Wmax.) or a total of
1A~2.22A (26.64W max.) at +12V". I don't know if is the variable
output(controllable range), or if any value in between is the max fan rating
to connect
 
Shazam.
pc ics, superi/os OR
http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/627hf.pdf
pp39-70...

It looks like 3 fans can be turned on or off and the speed can be varied
according to various temp ranges.

So it looks like I'll need a 3-pin with tach output that is variably speed
controllable. Do I need a therm.... equipt fan mister?

I'd like an efficient one that is quiet, and conforms to the fan specs on
p2-27 of the manual (avail at asus.com). Possibly in red colour , not
UV, or LED. To match the SATA, and soon to be IDE and FLOPPY round red.

the "3-pin CPU_FAN, PWR_FAN, CHA_FAN fan
connectors support cooling fans of 350mA~740mA (8.88Wmax.) or a total of
1A~2.22A (26.64W max.) at +12V". I don't know if is the variable
output(controllable range), or if any value in between is the max fan rating
to connect
 
Shazam.
pc ics, superi/os OR
http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/627hf.pdf
pp39-70...

It looks like 3 fans can be turned on or off and the speed can be varied
according to various temp ranges.

So it looks like I'll need a 3-pin with tach output that is variably speed
controllable. Do I need a therm.... equipt fan mister?

I'd like an efficient one that is quiet, and conforms to the fan specs on
p2-27 of the manual (avail at asus.com). Possibly in red colour , not
UV, or LED. To match the SATA, and soon to be IDE and FLOPPY round red.

the "3-pin CPU_FAN, PWR_FAN, CHA_FAN fan
connectors support cooling fans of 350mA~740mA (8.88Wmax.) or a total of
1A~2.22A (26.64W max.) at +12V". I don't know if is the variable
output(controllable range), or if any value in between is the max fan rating
to connect
 
kgs said:
If you buy a 550W psu and only need 230W (as ASUS recommends for an average
system on p.2-28 of the manual) you are generating a lot more heat than you
need. But if the "duty-cycle" is much better, you may actually develop less
heat.
Click to expand...

Go buy a Dell or a Compaq or a HP. Their engineers would have already
done all of the calculations and the worrying for you. :-))
 
"kgs" said:
Here's a scan of my psus box.

Besides the rectangular 4-pin (molex?) power connectors, there is only the
20-pin rectangular mobo power plug and a square 4-pin 12V power mobo plug
coming from the psu.

How can I get the fan speed monitoring done? Is it on the 4-pin square
connector? Hopefully it is. What are they talking about "supports fan speed
monitoring".

The mobo may get the temp of the psu from the psu 4-pin 12V connector.
Hopefully it is.

If I attach a thermo(please insert whatever type word here if you can e.g
meter, couple) from the hottest part of the psu to the power supply thermal
monitoring connector (2-pin TRPWR) of my mobo (2-28 manual) will it play a
part in any equation, or wil it be monitored in either BIOS or software (eg
PCProbe). I have a cusl2-c and it doesn't have the option to monitor psu
heat, only cpu and mobo temp monitoring. As well as cpu, chassis, and psu
fan speeds. Not using mobo w/ 4-pin sq. 12V at the moment, so I have
disabled the chassis and psu fan speed monitoring so my pc isn't noisy and
blinky.




begin 666 powmax.jpg
Click to expand...

I agree with Mistoffolees, you have to slow down a bit. The idea is, you
post an article on USENET with a descriptive title, and then you wait for
an answer or answers to appear. If the person responding to you asks for
more information, then a reply with the information is useful.

By placing many interesting and diverse questions in 12 posts, I am overwhelmed
and cannot respond to each and every post. It would take me all day to
write twelve detailed replies etc. I hope you were not expecting a reply to
each of those posts to be drafted. What takes you five minutes to ask,
takes me an hour to answer.

Sometimes it is useful to start separate threads for unrelated questions,
but even then, you could be in for some flameage if you place a whole bunch
of questions in a group in close time proximity to one another. The group
expects you to do some research on your own, so that your questions can
be focused on the things you are uncertain about, as opposed to writing
a very broad answer covering every possible combination of hardware.

On the one hand, I hate to be a "net nazi", but on the other hand I want
you to understand how best to get the information you need, by not alienating
the people who can potentially answer your questions. (I only mention this
because you said you weren't happy that people hadn't responded to your
other posts...)

Also, this is a non-binary group, which means that attaching JPEG files would
normally be frowned on. Some people effectively have to pay per byte of
download, and a large binary in an otherwise text-only group is an expensive
and unwelcome surprise (people in Europe pay for local phone service by
the minute, so they are paying for your 1MB scan of the PSU as we speak).
The people in sci.electronics use some alt.binaries group for their
schematics and the like, but I don't remember right off hand which one
they use.

Back to your questions:
What are they talking about "supports fan speed monitoring".
Click to expand...

Fan speed monitoring means they will offer you the tachometer signal coming
from the power supply fan. Examine your power supply carefully and you will
find a two wire cable with a three pin style connector on the end. The
two wires carry the tachometer signal and a ground signal. If this three
pin connector is connected to a motherboard three pin fan header, then
the monitor chip can count fan revolutions and make them available while
Windows is running, via Motherboard Monitor (MBM) or Asus Probe.

Another option some power supplies offer, is PSU temperature sensing. If
you have a power supply with this feature, you will find a two wire cable
with a two pin connector. This connects to a two pin header on the motherboard
with a name like TRPWR or the like. Inside the PSU will be a thermistor
(a NTC negative temperature coefficient resistor) whose resistance changes
with temperature. At 25C, this thermistor will have a resistance of 10K ohms
(at least that is the defacto standard), so an Asus TRPWR header will give
reasonably accurate readings near 25C. (Note: Do not attempt to add a
thermistor to the PSU yourself - there are lethal DC voltages in there
and you never know whether the bleeder resistors on the big electrolytic
capacitors are doing their jobs or not. And draining the caps by placing
a screwdriver blade across the two electrodes on a cap can deafen you!)
If you buy a 550W psu and only need 230W (as ASUS recommends for an
average system on p.2-28 of the manual) you are generating a lot more
heat than you need. But if the "duty-cycle" is much better, you may
actually develop less heat.
Click to expand...

The waste heat from a power supply is for the most part a linear function
of the output current. Say the motherboard is drawing 100 watts from the
power supply, and the power supply has a stated efficiency of 80%. This
means it draws (1/0.80)*100W = 125W from the wall, and 25W is discarded
as heat. If you are drawing 230W at the output, then the waste heat is
57.5W. If a 350W and a 550W supply have the same 80% efficiency rating,
and each is asked to deliver 230W, they both waste 57.5W in the form of
heat. To reduce heat, find the most efficient supply you can. Computer
PSUs are not very efficient, and finding even an 80% efficient computer
PSU is difficult. Check the specs on Fortron supplies and compare them
to some of the others.
Unless you can control the speed inline (how about one of the many
faceplates). Can you then still have your speed read monitored by
bios/software, and have your alarm if threshold rotaion monitored
this way?
Click to expand...

First of all, to monitor fan speed you need the tachometer signal.
If three wires come from the fan body, then the tach signal exists.

Fans which draw large currents from +12V or fans equipped with a
variable or switchable resistor to vary fan speed, tend to have a
four pin (disk drive style) Molex connector to provide the power.
When you buy a fan with this option, there may be a single wire
with a three pin connector on the end. The single wire carries the
tachometer signal, and when the three pin connector is connected
to a three pin header on the motherboard, you can monitor the
fan speed. Then, an alarm function will work properly.
The key word here I guess is CONTROL. I have yet to discover if
there is a control for the cpu fan. Is this in fact true, and is
this adjusted by the asus BIOS and/or software?
Click to expand...

If the motherboard supports a fan control option, it will quite likely
be called Q-fan by Asus. Since the CPU fan is associated with whatever
device is used to monitor the CPU temperature, it makes sense that only
the CPU fan is controllable. The other fans are generally not controlled
by the motherboard. You can control other fans in your computer with
third party drive bay controller boxes (Thermaltake Nexus?), but at
least some of these cheap controllers use a simple variable resistor
and the design quality is terrible (high failure rate).

For chassis fans, I would recommend you read as many specs as you can,
especially on sites like http://www.quietpc.ca/casefans.html or the like.
Sleeve bearing fans are quieter than ball bearing fans, but on the
cheap ones, the bearings become noisy/dry out in a matter of days. An
exception might be the Panasonic Panaflo sleeve bearing fans. A large,
low RPM fan is quieter than a small high RPM fan. Many cases have
space for a 80mm fan and that makes a good choice for a chassis fan.
(Since you are in Canada, take a look at bigfootcomputers.com for
Panaflo fans. Use the search engine and search on Panaflo for a list
of what is available.)

Acoustic sound insulation material placed inside the case is generally
not a good idea, if you believe the people who report a significant
temperature rise after the padding is added inside the case.

To start with, don't go overboard with fans. I recommend one fan in the
back of the case plus the fan in the PSU as a minimum. Add the fan to
the front of the case if you find the motherboard temperature is
climbing too much. People who have eight fans in their case probably
don't need all of them in order to ensure their electronics have a long
life.

Hard drive temperature is important, but in combination with the room
humidity level. If your computer is in an air conditioned room, there
is little to worry about, as the humidity will be 40% or so. If the
computer is going to be in an un air conditioned space, then you should
think a little about drive cooling. Buying a low power drive is a good
start - check http://storagereview.com/comparison.html and see their
"net drive temperature" chart for some good choices in low delta T
drives.

For your CPU fan, you can use the Intel HSF that comes with the retail
CPU. This is a quality product with a reasonable fan for the job. Since
the fan has a built in thermal control function, you can rely on it alone
or you can use Q-fan as well. Some experimenting will be needed to see
what combination of controls gives you consistent CPU temperatures.

A Zalman CNPS7000 HSF is the current champion in terms of quiet and cool,
but check the engineering information on the page carefully, such as
dimensions and the like, because this thing is big and heavy.
bigfootcomputers.com has these, as does bytewizecomputers.com .
Replacing the Intel HSF with one of these will at least make the CPU
cooling inaudible.

http://www.zalman.co.kr/english/product/cnps7000a-alcu.htm

That should give you some ideas to get started. Note that when battling
noise, that once one source is made quiet, another part will become audible.
The computer can never be too quiet. You could always do what the guys
with the Delta 6800 RPM fans do, and turn up the stereo.

HTH,
Paul
 
GHalleck said:
Go buy a Dell or a Compaq or a HP. Their engineers would have already
done all of the calculations and the worrying for you. :-))
Click to expand...

only to be over-ruled by the accountants and marketing...
 
Thank you. I am keeping vey busy. I am trying to learn as much as
possible.. I just considered going throuth the asus manual front to back for
the third time and asking a question, or making a statement about everything
in it that applies to me, or may apply in the future.

My question was originally is Pc Probe/Q-fan/BIOS and my P4C800-E deluxe
mobo going to require a fan of a certain type and why, because I need a new
one and like being prepared. I was probably going to go to bigfoot for my
very next purchases anyways. I will do as you say. But if I ask any more,
such as anything, the majority of which I have already asked, I am sure not
to get a staight answer. Granted I may jump the gun, and it wil take me
several readings before I get everything understood. Non-intentionally, the
effect of my posts is that I plow through to the most probable solution. I
do not think I support mis-information or extraneous matter. I don't care
to explain. I'll be back and would be happy to hear from anybody. And I
hope others are learning from my journey.
 
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