A8N-SLI Premium -- Cooling

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Peter Finney

While Googling I came across an old thread on this topic, and realised
that my experiences with this board might be interesting to other Asus
devotees.

I have recently upgraded my system with:

Asus A8N-SLI Premium motherboard.
1GBgyte Ram (two Samsung 512MByte sticks).
Asus (Nvidia) 6600 Silencer (Fanless) graphics Card.
AMD Athlon 64 X2 4400+ (dual core) - Retail package with AMD heatsink
and Fan.

Before proceeding to discuss cooling let me say that performance is
scintillating!

Cooling:

The system is in a medium-sized tower case fitted with a 3-fan
temperature controlled 525W power supply (Hiper) . There are 2 IDE
hard discs, and 2 IDE optical drives. The case is fitted with two
80mm 2.4w additional fans - one exhaust at the top - one inlet at the
bottom.

Even before I bought this Motherboard I realised that there was a
cooling issue that needed to be addressed. This is because the
chassis heatsink which is next to the Processor socket, and which
cools the voltage regulators, also cools the chipset (southbridge) via
a heatpipe. This eliminates the need for a chipset fan. However the
shared heatsink relies on warm exhaust air from the processor cooling
fan for its own cooling.

This means that:

a. The shared heatsink (and hence the southbridge) could run hotter
than the CPU.

b. If the CPU fan speed is controlled based on the CPU temperature,
the southbridge (and possibly the voltage regulators) could overheat.

My initial investgations led me to beleive that the built-in CPU fan
speed control did not properly take account of this feature -
and to that extent the motherboard could be said to have a design
flaw.

I have fitted an mcubed T-balancer fan control system which has
allowed to me investigate and manage this issue. There are 8
temperature sensors fitted as follows:

CPU heatsink (2 sensors - for rendundancy).
Shared regulator/soutbridge heatsink (2 sensors).
Graphics Card (stuck on the circuit card on the upper side above the
heatsink, since the heatsink is underneath the card when mounted in
the case).
Hard drive 0
Hard drive 1
Southbridge (mounted directly on the heat pipe fitting)

In addition I have Mother Board Monitor to monitor the motherboard and
harddrive temperature sensors:
CPU
Motherboard
Auxuliary (case?)
HD1 (HD0 does not have an internal temp sensor)

So I am monitoring 11 temperatures.

The fans are controlled as follows:
CPU fan speed- based on CPU and shared heatsink temperature.
Case fan speed - based on shared heatsink/VGA card/hard drive
temperatures. The two case fans have different speed/temperature
profiles - designed to run the upper exhaust fan harder initially.

As expected from the start -
a. The CPU runs cooler than the shared heatsink.
b. It is essential to run the CPU fan fast enough to cool the
shared heatsink effectively.

I tested the system by running (Freestone) Video Card Stability Test.
This runs the graphics processor flat out, and shows CPU1 at 55% and
CPU2 at 54%. (Running other apps to get the CPUs up to 100% does not
make any visible difference).

After 15 minutes - Temperatures have stabilised at:

Room temperature: 23C

MotherBoard Monitor:
CPU: 39C
'Case': 32C
Motherboard 32C
HD1: 37C

Mcubed T-balancer:
CPU: 38.5C/38.5C
Shared Heatsink: 43.0C/44.0C
HD0: 34.5C
HD1: 37.5C
VGA: 42.0C
Southbridge (Chipset): 39.5C

Fan Speed (percent max)
CPU 64%
Upper exhaust 46%
Lower inlet 22%

Conclusions:

1. mcubed T-balancer rocks - the system is very quiet!

2. The only advantage of the 'Premium' version of the A8N is the
elimination of the chipset heatsink and fan. This is supposed to
reduce noise. However - you have to run the CPU fan faster to cool
the combined heatsink - thus probably negating the noise advantage.
Also this combined heatsink, which depends on exhaust air from the CPU
cooler, makes temperature (and noise) control more difficult. If you
are going to run the CPU fan at 100% rpm all the time - that does not
matter, but if you are going to do that you certainly would not be
hearing the noise from a chipset cooler fan! The mcubed T-balancer
has a 4th fan control which could control a chipset fan.

3. Asus got this a bit wrong - in retrospect I would probably
have bought the A8N Deluxe.

However it is a super MB.

Note: I am not an overclocker - what I need is a fast, stable, quiet
system - which I now have.
Peter Finney
Liphook
Hampshire
England
 
While Googling I came across an old thread on this topic, and realised
that my experiences with this board might be interesting to other Asus
devotees.

I have recently upgraded my system with:

Asus A8N-SLI Premium motherboard.
1GBgyte Ram (two Samsung 512MByte sticks).
Asus (Nvidia) 6600 Silencer (Fanless) graphics Card.
AMD Athlon 64 X2 4400+ (dual core) - Retail package with AMD heatsink
and Fan.

Before proceeding to discuss cooling let me say that performance is
scintillating!

Cooling:

The system is in a medium-sized tower case fitted with a 3-fan
temperature controlled 525W power supply (Hiper) . There are 2 IDE
hard discs, and 2 IDE optical drives. The case is fitted with two
80mm 2.4w additional fans - one exhaust at the top - one inlet at the
bottom.

Even before I bought this Motherboard I realised that there was a
cooling issue that needed to be addressed. This is because the
chassis heatsink which is next to the Processor socket, and which
cools the voltage regulators, also cools the chipset (southbridge) via
a heatpipe. This eliminates the need for a chipset fan. However the
shared heatsink relies on warm exhaust air from the processor cooling
fan for its own cooling.

This means that:

a. The shared heatsink (and hence the southbridge) could run hotter
than the CPU.

b. If the CPU fan speed is controlled based on the CPU temperature,
the southbridge (and possibly the voltage regulators) could overheat.

My initial investgations led me to beleive that the built-in CPU fan
speed control did not properly take account of this feature -
and to that extent the motherboard could be said to have a design
flaw.

I have fitted an mcubed T-balancer fan control system which has
allowed to me investigate and manage this issue. There are 8
temperature sensors fitted as follows:

CPU heatsink (2 sensors - for rendundancy).
Shared regulator/soutbridge heatsink (2 sensors).
Graphics Card (stuck on the circuit card on the upper side above the
heatsink, since the heatsink is underneath the card when mounted in
the case).
Hard drive 0
Hard drive 1
Southbridge (mounted directly on the heat pipe fitting)

In addition I have Mother Board Monitor to monitor the motherboard and
harddrive temperature sensors:
CPU
Motherboard
Auxuliary (case?)
HD1 (HD0 does not have an internal temp sensor)

So I am monitoring 11 temperatures.

The fans are controlled as follows:
CPU fan speed- based on CPU and shared heatsink temperature.
Case fan speed - based on shared heatsink/VGA card/hard drive
temperatures. The two case fans have different speed/temperature
profiles - designed to run the upper exhaust fan harder initially.

As expected from the start -
a. The CPU runs cooler than the shared heatsink.
b. It is essential to run the CPU fan fast enough to cool the
shared heatsink effectively.

I tested the system by running (Freestone) Video Card Stability Test.
This runs the graphics processor flat out, and shows CPU1 at 55% and
CPU2 at 54%. (Running other apps to get the CPUs up to 100% does not
make any visible difference).

After 15 minutes - Temperatures have stabilised at:

Room temperature: 23C

MotherBoard Monitor:
CPU: 39C
'Case': 32C
Motherboard 32C
HD1: 37C

Mcubed T-balancer:
CPU: 38.5C/38.5C
Shared Heatsink: 43.0C/44.0C
HD0: 34.5C
HD1: 37.5C
VGA: 42.0C
Southbridge (Chipset): 39.5C

Fan Speed (percent max)
CPU 64%
Upper exhaust 46%
Lower inlet 22%

Conclusions:

1. mcubed T-balancer rocks - the system is very quiet!

2. The only advantage of the 'Premium' version of the A8N is the
elimination of the chipset heatsink and fan. This is supposed to
reduce noise. However - you have to run the CPU fan faster to cool
the combined heatsink - thus probably negating the noise advantage.
Also this combined heatsink, which depends on exhaust air from the CPU
cooler, makes temperature (and noise) control more difficult. If you
are going to run the CPU fan at 100% rpm all the time - that does not
matter, but if you are going to do that you certainly would not be
hearing the noise from a chipset cooler fan! The mcubed T-balancer
has a 4th fan control which could control a chipset fan.

3. Asus got this a bit wrong - in retrospect I would probably
have bought the A8N Deluxe.

However it is a super MB.

Note: I am not an overclocker - what I need is a fast, stable, quiet
system - which I now have.
Peter Finney
Liphook
Hampshire
England
Click to expand...


You have forgotten something that Asus didn't. The large-area
switch-regulator silicon can withstand a LOT more heat than the tiny,
tiny transistors and nanometer 'wires' inside the integrated silicon.
Quite happy at temperatures up to 70 degrees C heat-sink-tip temps
(80-85 silicon-temps) -finger-fry time. The rear case fan and to a
slightly lesser extent the adjacent power-supply fan will more than
adequately cool this regulator (shared) heat sink. However, you
MUSTalways have adequate air-flow over the regulator CAPACITORS.
Regardless of temperature-rating, electrolytic capacitors gradually
dry out and eventually long-term fail with continuous excess heat. The
stock CPU coolers always have a dead-air area around the CPU socket
just where the capacitors are installed...adjacent to the base of the
heat-sink on very hot piece of silcon (the CPU) The rear case fan may
ventilate enough, but the best solution to cool the capacitors is to
install a Zalman CNPS7000 (or 7700, if you have the room) flower
CPU-cooler. And don't forget to ensure that there is adequate
POSITIVEair-flow INTO your computer-case -- the exhaust fans will work
far more efficiently. For example, installing one of the quiet dual
or triple-fan HD coolers in an EMPTY slot (with no HD) will help
positively ventilate the memory (and CPU) area.

Anyway, your 'cooling-solution' is a little overkill for the
trivial-wattage system you are running. Not a wise use of your
financial resources. Your whole system is probably not taking more
than 250 watts from the power-supply. You have some nice low
temperatures --- they sure do not need any specialized monitoring
whatsoever. For example, since you are not overclocking the
processor, then it will run as happily as a clam with at least
60degrees C core-temp as monitored by the motherboard, with
zero effect on long-term reliability.

BTW, the Zalman CNPS CPU-coolers are a LOTquieter and more efficient
than any stock CPU cooler. You should have bought one of those
(~ $30-$40) instead of wasting your money on the temperature
monitoring hardware.

John Lewis
- Technology early-birds are flying guinea-pigs.
 
You have forgotten something that Asus didn't. The large-area
switch-regulator silicon can withstand a LOT more heat than the tiny,
tiny transistors and nanometer 'wires' inside the integrated silicon.
Quite happy at temperatures up to 70 degrees C heat-sink-tip temps
(80-85 silicon-temps) -finger-fry time. The rear case fan and to a
slightly lesser extent the adjacent power-supply fan will more than
adequately cool this regulator (shared) heat sink.
Click to expand...

I had not forgotten anything. I was not worried about the cooling of
the regulators etc - but the cooling of the Chipset (southbridge) -
which shares the same heatsink. Clearly the chipset cannot be cooler
than this heatsink - regardless of the efficiency of the heatpipe.

As to the 'overkill' of using the mcubed T-balancer on this system -
the point is not to overcool the system - but to run it as quietly as
possible.




Peter Finney
Liphook
Hampshire
England
 
I had not forgotten anything. I was not worried about the cooling of
the regulators etc - but the cooling of the Chipset (southbridge) -
which shares the same heatsink. Clearly the chipset cannot be cooler
than this heatsink - regardless of the efficiency of the heatpipe.
Click to expand...

And this heatsink is deliberately placed by Asus in the case-fan
area... no problem cooling it, so it will get nowhere near even 50
degrees C, between the ventilation from the case-fan and the
power-supply fan(s), especially if the inlet air is fan-aided or
reasonably unrestricted ( large perfs in the front of the case
and/or perfs in the lower side-cover )
As to the 'overkill' of using the mcubed T-balancer on this system -
the point is not to overcool the system - but to run it as quietly as
possible.
Click to expand...

You installed a power-supply with 3 fans, not especially designed
for low-noise (at least I can't find any specific reference to
low-noise or dba ratings in the Hiper PS specs), you are using 80mm
case-fans instead of 120mm fans, and you are using the stock (noisy)
CPU cooler, so you do not seem to be critically concerned with noise.

Seems as if the mcubed is a totally unnecessary expense in your
particular situation, when using lower-speed fans of larger size
would have achieved the same or better result at much lower
cost and even fixed fan speeds.

If you were running a dual-SLI 7800GTX setup and seriously
overclocking your CPU, then you might have some justification
in using the mcubed to auto-balancing the fan-speeds for optimum
temperatures, but only after first installing larger, slower case and
CPU fans and selecting a power-supply for its audible-noise
characteristics.

BTW, the CNPS 7000 can very nicely help cool the subject heat-sink
as well as the CPU. So you would actually have triple-cooling of this
heatsink... and probably be able to run all the now-larger fans at
minimum speed.

John Lewis
Peter Finney
Liphook
Hampshire
England
Click to expand...

- Technology early-birds are flying guinea-pigs.
 
And this heatsink is deliberately placed by Asus in the case-fan
area... no problem cooling it, so it will get nowhere near even 50
degrees C, between the ventilation from the case-fan and the
power-supply fan(s), especially if the inlet air is fan-aided or
reasonably unrestricted ( large perfs in the front of the case
and/or perfs in the lower side-cover )
Click to expand...

I am using an existing case - with no case fan in that area - the only
'built-in' cooling is by the Power Supply fans.
You installed a power-supply with 3 fans, not especially designed
for low-noise (at least I can't find any specific reference to
low-noise or dba ratings in the Hiper PS specs), you are using 80mm
case-fans instead of 120mm fans, and you are using the stock (noisy)
CPU cooler, so you do not seem to be critically concerned with noise.
Click to expand...

The power supply auto-controls its fan speeds . With my case fans off
- it runs fast and is noisy - with them on it runs slow and quietly.

I am very concerned about noise - the system runs 24/7 (mailservers
etc) and is right next to the bedrooms in this bunglow. It is now
VERY quiet. I am happy!
Seems as if the mcubed is a totally unnecessary expense in your
particular situation, when using lower-speed fans of larger size
would have achieved the same or better result at much lower
cost and even fixed fan speeds.

If you were running a dual-SLI 7800GTX setup and seriously
overclocking your CPU, then you might have some justification
in using the mcubed to auto-balancing the fan-speeds for optimum
temperatures, but only after first installing larger, slower case and
CPU fans and selecting a power-supply for its audible-noise
characteristics.
Click to expand...

Everything you say is absolutely true, but what you are also saying is
that if I had thown away my existing case, power supply and fans, and
bought replacements and replaced the AMD CPU cooler and fan with
another bought-in item - I would have saved money compared with using
the T-Balancer. I think not - but that would be an interesting
calculation.
BTW, the CNPS 7000 can very nicely help cool the subject heat-sink
as well as the CPU. So you would actually have triple-cooling of this
heatsink... and probably be able to run all the now-larger fans at
minimum speed.

John Lewis
Click to expand...

This has been an interesting conversation - but there is a grave
danger it will become a contest about who has the last word. So bye
for now on this subject.
Peter Finney
Liphook
Hampshire
England
 
While Googling I came across an old thread on this topic, and realised
that my experiences with this board might be interesting to other Asus
devotees.

I have recently upgraded my system with:

Asus A8N-SLI Premium motherboard.
1GBgyte Ram (two Samsung 512MByte sticks).
Asus (Nvidia) 6600 Silencer (Fanless) graphics Card.
AMD Athlon 64 X2 4400+ (dual core) - Retail package with AMD heatsink
and Fan.

Before proceeding to discuss cooling let me say that performance is
scintillating!

Cooling:

The system is in a medium-sized tower case fitted with a 3-fan
temperature controlled 525W power supply (Hiper) . There are 2 IDE
hard discs, and 2 IDE optical drives. The case is fitted with two
80mm 2.4w additional fans - one exhaust at the top - one inlet at the
bottom.

Even before I bought this Motherboard I realised that there was a
cooling issue that needed to be addressed. This is because the
chassis heatsink which is next to the Processor socket, and which
cools the voltage regulators, also cools the chipset (southbridge) via
a heatpipe. This eliminates the need for a chipset fan. However the
shared heatsink relies on warm exhaust air from the processor cooling
fan for its own cooling.

This means that:

a. The shared heatsink (and hence the southbridge) could run hotter
than the CPU.

b. If the CPU fan speed is controlled based on the CPU temperature,
the southbridge (and possibly the voltage regulators) could overheat.

My initial investgations led me to beleive that the built-in CPU fan
speed control did not properly take account of this feature -
and to that extent the motherboard could be said to have a design
flaw.

I have fitted an mcubed T-balancer fan control system which has
allowed to me investigate and manage this issue. There are 8
temperature sensors fitted as follows:

CPU heatsink (2 sensors - for rendundancy).
Shared regulator/soutbridge heatsink (2 sensors).
Graphics Card (stuck on the circuit card on the upper side above the
heatsink, since the heatsink is underneath the card when mounted in
the case).
Hard drive 0
Hard drive 1
Southbridge (mounted directly on the heat pipe fitting)

In addition I have Mother Board Monitor to monitor the motherboard and
harddrive temperature sensors:
CPU
Motherboard
Auxuliary (case?)
HD1 (HD0 does not have an internal temp sensor)

So I am monitoring 11 temperatures.

The fans are controlled as follows:
CPU fan speed- based on CPU and shared heatsink temperature.
Case fan speed - based on shared heatsink/VGA card/hard drive
temperatures. The two case fans have different speed/temperature
profiles - designed to run the upper exhaust fan harder initially.

As expected from the start -
a. The CPU runs cooler than the shared heatsink.
b. It is essential to run the CPU fan fast enough to cool the
shared heatsink effectively.

I tested the system by running (Freestone) Video Card Stability Test.
This runs the graphics processor flat out, and shows CPU1 at 55% and
CPU2 at 54%. (Running other apps to get the CPUs up to 100% does not
make any visible difference).

After 15 minutes - Temperatures have stabilised at:

Room temperature: 23C

MotherBoard Monitor:
CPU: 39C
'Case': 32C
Motherboard 32C
HD1: 37C

Mcubed T-balancer:
CPU: 38.5C/38.5C
Shared Heatsink: 43.0C/44.0C
HD0: 34.5C
HD1: 37.5C
VGA: 42.0C
Southbridge (Chipset): 39.5C

Fan Speed (percent max)
CPU 64%
Upper exhaust 46%
Lower inlet 22%

Conclusions:

1. mcubed T-balancer rocks - the system is very quiet!

2. The only advantage of the 'Premium' version of the A8N is the
elimination of the chipset heatsink and fan. This is supposed to
reduce noise. However - you have to run the CPU fan faster to cool
the combined heatsink - thus probably negating the noise advantage.
Also this combined heatsink, which depends on exhaust air from the CPU
cooler, makes temperature (and noise) control more difficult. If you
are going to run the CPU fan at 100% rpm all the time - that does not
matter, but if you are going to do that you certainly would not be
hearing the noise from a chipset cooler fan! The mcubed T-balancer
has a 4th fan control which could control a chipset fan.

3. Asus got this a bit wrong - in retrospect I would probably
have bought the A8N Deluxe.

However it is a super MB.

Note: I am not an overclocker - what I need is a fast, stable, quiet
system - which I now have.
Peter Finney
Liphook
Hampshire
England
Click to expand...

Very nice documentation, Peter! Interestingly, your CPU and chipset
temps are very similar to my results, at least the differences between
the two. I let the CPU fan (on my Thermalright XP120) be controlled
by Asus Q-Fan. The 120mm Panaflo runs at about 1,600 RPM. It's not
real slow, but even at this speed, it makes essentially no noise. My
room temp is 23°, the CPU (3500+) is 30° (not under load right now),
and the chipset is 37° (by MBM and Lavalys Everest).

Your statement that Asus forgot to realize that their chipset cooling
solution requires that the CPU-cooler fan be run faster than would
otherwise be necessary, however, does not seem to be based on any
factual information. What evidence do you have that it's important to
get the chipset as cool as you have it? I rather believe that your
rig would be perfectly stable and that its life would not be shortened
if you simply throttle the CPU fan down to a speed that gives you the
CPU temps you desire.

Parenthetically, your approach to achieving silence by using 80mm case
fans is unusual. As I'm sure you realize, there are much easier and
better ways, but, admittedly, that would involve buying new hardware.

Ron
 
Very nice documentation, Peter! Interestingly, your CPU and chipset
temps are very similar to my results, at least the differences between
the two. I let the CPU fan (on my Thermalright XP120) be controlled
by Asus Q-Fan. The 120mm Panaflo runs at about 1,600 RPM. It's not
real slow, but even at this speed, it makes essentially no noise. My
room temp is 23°, the CPU (3500+) is 30° (not under load right now),
and the chipset is 37° (by MBM and Lavalys Everest).

Your statement that Asus forgot to realize that their chipset cooling
solution requires that the CPU-cooler fan be run faster than would
otherwise be necessary, however, does not seem to be based on any
factual information. What evidence do you have that it's important to
get the chipset as cool as you have it? I rather believe that your
rig would be perfectly stable and that its life would not be shortened
if you simply throttle the CPU fan down to a speed that gives you the
CPU temps you desire.

Parenthetically, your approach to achieving silence by using 80mm case
fans is unusual. As I'm sure you realize, there are much easier and
better ways, but, admittedly, that would involve buying new hardware.

Ron
Click to expand...

The evidence is shown on the A8N32 Deluxe web page:

http://usa.asus.com/products4.aspx?l1=3&l2=15&l3=226&model=744&modelmenu=1

"Optional Fan (for Water-Cooling or Passive-Cooling only)

Maximize performance and minimize noise! The optional fan is
specifically designed to provide sufficient airflow over the CPU
power modules and chipset area when water-cooling or passive-cooling
is utilized, ensuring effective heat dissipation for the entire
system."

The downloadable manual wasn't there when I looked earlier today, so
there is no way to check to see whether the "optional fan" is
really optional or is included. And, with the arrangement of MOSFET
heatsinks, I cannot see how that fan would be mounted.

So, they did think about the case of people not using an XP-120,
but just on their latest design.

Maybe Asus really do read the newsgroups ? :-)

Paul
 
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