Prescott 40C above ambient?

[Gregory]

I'm running a prescott 3.2E on an abit is7 (latest bios version, 24) and I
just can't seem to cool this beast. I'm not overclocking and I have no other
hot components in the case. I'm using a Zalman CNPS7000B-AlCu cooler set to
full. It gets pretty hot around here, and room temperature is normally
around 30C (bound to go above that in the coming months). Here's the
relevent troubleshooting info:

I have no case fans (bad! but read on...) and the temperatures read:
Case: 42C
Idle: 55C (sometimes goes down to 50ish for some reason)
Load: over 75C (I haven't waited long enough to see how far up it goes)

Before investing in case fans, I've taken two massive room fans and I'm
blowing them straight into the side of the case (with the case open,
obviously). Results:

Case: 32-33C (2-3 degrees above room temp)
Idle: 50C
Load: 73C (stable)

This is a full 40 degrees above case temperature, and definitely far far too
hot. I can't even use winrar without it overheating...

What could be wrong? The HSF is fitted tightly. I've been told that it isn't
good enough for prescotts, though the website claims it is, as long as it's
set to full. Would the zalman really be worse than the stock intel HSF?
(which I don't have, btw) I haven't tried uninstalling it and reapplying the
thermal paste from scratch, so that might be an idea.

As for case fans, I don't think they will provide better performance than
the room fans blowing on full (though if I do solve the problem, then
obviously I will get some fans and not just leave the room fans ;-))

Any other things to try short of buying another more massive HSF? (geforce
4 and one hard disk...) Google tells me a lot of people have had this
problem, but it also finds a lot of people which run prescotts relatively
"cool" (ie. below 50C under load).

Any advice greatly appreciated!

Gregory

 

[S.Heenan]

I have no case fans (bad! but read on...) and the temperatures read:
Case: 42C
Idle: 55C (sometimes goes down to 50ish for some reason)
Load: over 75C (I haven't waited long enough to see how far up it
goes)

Get two 80mm fans, of 35CFM or greater. One input in the front and one
exhaust in the back. Keep the case closed for proper airflow.

 

[Gregory]

Get two 80mm fans, of 35CFM or greater. One input in the front and one
exhaust in the back. Keep the case closed for proper airflow.

Thanks, but do you think this will solve the problem given the rest of my
post? I realise putting external room fans won't create a directed air flow
the same way case fans will, but they sure move a lot of air in and out of
the case.

My case has a cage for a 120mm fan in front and an 80mm fan at the back, and
the plan is to fit fans to both of these (as well as to the 90mm cage on the
side of the case right "above" the cpu). I'm thinking of getting the fastest
possible fans - at this point I don't care anymore about the noise, I just
want my system to work! The adjustable Thermaltake A2016/17/18 fans look
good - rated at 73/79/94CFM max - that way I can slow them down while
"desktopping" and set them to fast while gaming or video encoding.

Gregory

 

[bgd]

That zalman isnt a very large heatsink. especially for the 3.2. try a
thermaltake xp-90
theres a copper version and original or other larger lightweight. I have a
hot 2.8e prescott staying very calm cool with reverse cooling (which really
doesnt matter) on the xp90. That zalman you are running is kinda silly from
an engineering point of view.Very ineffective just to look at-
good luck
may the heatsink be with you...

 

[Paul]

I'm running a prescott 3.2E on an abit is7 (latest bios version, 24) and I
just can't seem to cool this beast. I'm not overclocking and I have no other
hot components in the case. I'm using a Zalman CNPS7000B-AlCu cooler set to
full. It gets pretty hot around here, and room temperature is normally
around 30C (bound to go above that in the coming months). Here's the
relevent troubleshooting info:

I have no case fans (bad! but read on...) and the temperatures read:
Case: 42C
Idle: 55C (sometimes goes down to 50ish for some reason)
Load: over 75C (I haven't waited long enough to see how far up it goes)

Before investing in case fans, I've taken two massive room fans and I'm
blowing them straight into the side of the case (with the case open,
obviously). Results:

Case: 32-33C (2-3 degrees above room temp)
Idle: 50C
Load: 73C (stable)

This is a full 40 degrees above case temperature, and definitely far far too
hot. I can't even use winrar without it overheating...

What could be wrong? The HSF is fitted tightly. I've been told that it isn't
good enough for prescotts, though the website claims it is, as long as it's
set to full. Would the zalman really be worse than the stock intel HSF?
(which I don't have, btw) I haven't tried uninstalling it and reapplying the
thermal paste from scratch, so that might be an idea.

As for case fans, I don't think they will provide better performance than
the room fans blowing on full (though if I do solve the problem, then
obviously I will get some fans and not just leave the room fans ;-))

Any other things to try short of buying another more massive HSF? (geforce
4 and one hard disk...) Google tells me a lot of people have had this
problem, but it also finds a lot of people which run prescotts relatively
"cool" (ie. below 50C under load).

Any advice greatly appreciated!

Gregory

The thermal resistance of the CNPS7000 AlCu is 0.22 to 0.29C/W.
(as stated in the papers that come in the package). With the fan
connected directly to the motherboard header and the fan getting
the full +12V, you should get the full 0.22C/W performance.
40C / 0.22C/W = 182W. The processor would have to be dissipating
182W to have a 40C temperature rise over computer case ambient
(mobo temp).

The 3.2E processor is only 89W TDP, as stated here.

http://processorfinder.intel.com/scripts/details.asp?sSpec=SL88K

This means the heatsink is _not_ making good contact. Poor
contact would mean theta_R is higher than 0.22C/W . Pull the
heatsink and check the thermal grease pattern, to see if the
heatsink is making good contact.

The processor is probably going into thermal throttle mode, which
means it isn't even dissipating 89W. Thermal throttle mode is
described here, and there is a program that can show the slowdown
of the CPU clock.

http://www.digit-life.com/articles2/cpu/intel-thermal-features-p4.html
http://cpu.rightmark.org/download.shtml

I have a CNPS7000, and you must have air movement to pull hot air
away from the CNPS7000. Extra case fans are required to do it.
It also helps, to have a computer case large enough, to make
room between the PSU and the CNPS7000.

Even if you add fans to a computer case, a fan can only do its
work, if the ventilation holes are big enough in the computer case.
On my Sonata case, removing the plastic grille on the front of the
case helped cool it down. That leaves room for my rear-mounted
case fan to cool the case.

Paul

 

[kony]

I'm running a prescott 3.2E on an abit is7 (latest bios version, 24) and I
just can't seem to cool this beast. I'm not overclocking and I have no other
hot components in the case. I'm using a Zalman CNPS7000B-AlCu cooler set to
full. It gets pretty hot around here, and room temperature is normally
around 30C (bound to go above that in the coming months). Here's the
relevent troubleshooting info:

I have no case fans (bad! but read on...) and the temperatures read:
Case: 42C
Idle: 55C (sometimes goes down to 50ish for some reason)
Load: over 75C (I haven't waited long enough to see how far up it goes)

Before investing in case fans, I've taken two massive room fans and I'm
blowing them straight into the side of the case (with the case open,
obviously). Results:

Case: 32-33C (2-3 degrees above room temp)
Idle: 50C
Load: 73C (stable)

You need the case fans. The CPU is not the only part that
needs to be cooled, it is merely the one many people focus
on. Hard drives, motherboard and power supply are also
quite susceptible to overheating but unfortunately you may
have no warning like with the CPU... until it's too late.

This is a full 40 degrees above case temperature, and definitely far far too
hot. I can't even use winrar without it overheating...

What could be wrong? The HSF is fitted tightly. I've been told that it isn't
good enough for prescotts, though the website claims it is, as long as it's
set to full. Would the zalman really be worse than the stock intel HSF?
(which I don't have, btw) I haven't tried uninstalling it and reapplying the
thermal paste from scratch, so that might be an idea.

Forget about heatsink manufacturer's claims as to what their
'sink can do, for years they've made optimistic claims that
don't pan out unless the system is in a refrigerator. Even
so, Paul has a good point that the 'sink should be doing
better than it is, perhaps you should remove it, clean it
and CPU off and apply a fresh very thin coat of synthetic
thermal compound (such as Arctic Alumina, Silver, or
whatever your favorite brand but ideally not silicone based
as that formulation doesn't fare as well over time).

As for case fans, I don't think they will provide better performance than
the room fans blowing on full (though if I do solve the problem, then
obviously I will get some fans and not just leave the room fans ;-))

Any other things to try short of buying another more massive HSF? (geforce
4 and one hard disk...) Google tells me a lot of people have had this
problem, but it also finds a lot of people which run prescotts relatively
"cool" (ie. below 50C under load).

Any advice greatly appreciated!

Check your CPU voltage, and consider air-conditioning for
the room... > 30C just isn't very pleasant for the humans as
well as the system.

 

[paulmd]

I'm running a prescott 3.2E on an abit is7 (latest bios version, 24) and I
just can't seem to cool this beast. I'm not overclocking and I have no other
hot components in the case. I'm using a Zalman CNPS7000B-AlCu cooler set to
full. It gets pretty hot around here, and room temperature is normally
around 30C (bound to go above that in the coming months). Here's the
relevent troubleshooting info:

No one has mentioned Dust yet. But make sure your heat sinks, fans, and
intakes are free of dust.

 

[Gregory]

Excellent and informative post, thank you! Comments and questions below...

The thermal resistance of the CNPS7000 AlCu is 0.22 to 0.29C/W.
(as stated in the papers that come in the package). With the fan
connected directly to the motherboard header and the fan getting
the full +12V, you should get the full 0.22C/W performance.
40C / 0.22C/W = 182W. The processor would have to be dissipating
182W to have a 40C temperature rise over computer case ambient
(mobo temp).

This is good news, I hope you are right!

The 3.2E processor is only 89W TDP, as stated here.

http://processorfinder.intel.com/scripts/details.asp?sSpec=SL88K\

[actually it's
http://processorfinder.intel.com/scripts/details.asp?sSpec=SL7E5 but it's
the same thing]

This means the heatsink is _not_ making good contact. Poor
contact would mean theta_R is higher than 0.22C/W . Pull the
heatsink and check the thermal grease pattern, to see if the
heatsink is making good contact.

How can I tell from the pattern whether it's making good contact? Do big
"pools" mean contact is poor?

The processor is probably going into thermal throttle mode, which
means it isn't even dissipating 89W. Thermal throttle mode is
described here, and there is a program that can show the slowdown
of the CPU clock.

http://www.digit-life.com/articles2/cpu/intel-thermal-features-p4.html
http://cpu.rightmark.org/download.shtml

I downloaded the utility and it seems my processor never goes into throttle
mode. Look at this screenshot:
http://users.panafonet.gr/annalef/images/temp.JPG
Even though the recorded temperature is 75C, it hasn't throttled. Do I need
to activate the throttling or is it automatic? Could it simply be that the
motherboard reading is way off? I've read on usenet (maybe even in this
group) that Abit boards report higher than normal temperatures, but could
not confirm it.

I have a CNPS7000, and you must have air movement to pull hot air
away from the CNPS7000. Extra case fans are required to do it.
It also helps, to have a computer case large enough, to make
room between the PSU and the CNPS7000.

Even if you add fans to a computer case, a fan can only do its
work, if the ventilation holes are big enough in the computer case.
On my Sonata case, removing the plastic grille on the front of the
case helped cool it down. That leaves room for my rear-mounted
case fan to cool the case.

I have three fan cages on my case:
one on the side, above the CPU
(http://users.panafonet.gr/annalef/images/IMG_0001.JPG)
one at the back, below the PSU
(http://users.panafonet.gr/annalef/images/IMG_0002.JPG)
and one in front, but although the metal has holes like those in image 1
(bigger even), there is the front plastic over it, completely covering it!
Is that ridiculous or what?

The side vent seems to be decent (is it?), but the back one seems a little
rubbish. Should I try to, um, improve it somehow? Any advice on this issue?

Thank you again!
Gregory

 

[Gregory]

You need the case fans. The CPU is not the only part that
needs to be cooled, it is merely the one many people focus
on. Hard drives, motherboard and power supply are also
quite susceptible to overheating but unfortunately you may
have no warning like with the CPU... until it's too late.

OK, thanks. I plan to get the fans anyway. I just wanted to get to the core
of the problem first, so I can invest accordingly. If I need a massive
airflow to get it working, then I'll buy powerful fans, if not, then I
prefer to buy quiet ones, or maybe cheaper ones

Forget about heatsink manufacturer's claims as to what their
'sink can do, for years they've made optimistic claims that
don't pan out unless the system is in a refrigerator. Even
so, Paul has a good point that the 'sink should be doing
better than it is, perhaps you should remove it, clean it
and CPU off and apply a fresh very thin coat of synthetic
thermal compound (such as Arctic Alumina, Silver, or
whatever your favorite brand but ideally not silicone based
as that formulation doesn't fare as well over time).

OK, I'll try that as soon as I get my hands on some other thermal compound
(I think the one provided with the zalman was silcon based).

Check your CPU voltage, and consider air-conditioning for
the room... > 30C just isn't very pleasant for the humans as
well as the system.

Tell me about it, but that's not an option as I'm moving out in a few
months.

Thanks!
Gregory

 

[Gregory]

No one has mentioned Dust yet. But make sure your heat sinks, fans, and
intakes are free of dust.

While dust has now accumulated, I've had this problem since day 1 when the
case was new, the motherboard was new, and the HSF was new... I'll give it a
clean anyway.

Thanks,
Gregory

 

[Paul]

How can I tell from the pattern whether it's making good contact? Do big
"pools" mean contact is poor?

The thickness of the grease should be uniform across the surface.
If the grease is not spread all the way to the edges of the surface
to be cooled, then the thermal resistance goes up (because air is
an insulator). And if a _lot_ of grease shoots out the edges, it might
mean you applied it too thick. The purpose of thermal compound, is to
fill the surface irregularities, so that no (insulating) air is present.
If the thermal compound is applied too thick, that makes it harder for
the heat to get through.

Thermal compound should be applied thick enough, that a little bit
shows at the edge where the two surfaces meet. To _estimate_ the
amount required, place a half-rice-grain sized dot of compound on
the chip, fit the cooler, and see how much surface is covered when
the cooler is fitted to the CPU. That will help you estimate how
much additional compound is needed to fill the entire surface.

I downloaded the utility and it seems my processor never goes into throttle
mode. Look at this screenshot:
http://users.panafonet.gr/annalef/images/temp.JPG
Even though the recorded temperature is 75C, it hasn't throttled. Do I need
to activate the throttling or is it automatic? Could it simply be that the
motherboard reading is way off? I've read on usenet (maybe even in this
group) that Abit boards report higher than normal temperatures, but could
not confirm it.

Yes, the thermal diode readout could be defective. The processor uses
a second thermal diode for the throttling function, and at 75C, the
processor should be throttling. If your CPU fan can be controlled
by the hardware monitor interface on the motherboard ( by, for example,
Speedfan from almico.com ), you could slow the CPU fan down, and see
how much additional temperature rise it takes, before throttling
happens on the CPU.

I have three fan cages on my case:
one on the side, above the CPU
(http://users.panafonet.gr/annalef/images/IMG_0001.JPG)
one at the back, below the PSU
(http://users.panafonet.gr/annalef/images/IMG_0002.JPG)
and one in front, but although the metal has holes like those in image 1
(bigger even), there is the front plastic over it, completely covering it!
Is that ridiculous or what?

The side vent seems to be decent (is it?), but the back one seems a little
rubbish. Should I try to, um, improve it somehow? Any advice on this issue?

Thank you again!
Gregory

You must improve your cooling somehow. You claim your room temp is
30C and the air in the computer is 45C with the side of the case
fitted. That is a "delta_t" of 15C. A well cooled computer case should
have a delta_t of 7C. That means if the room air is 30C, the computer
case air should be 37C or lower.

The vents on your computer case are pretty small, and it is easy to
see how the temperatures would climb. Not every computer case can
be cut to bits, and fitted with better fans. Some older computer
cases are simply too small, or have irregular metal surfaces inside,
that make user modifications ineffective. Remember that a fan must be
fitted to a vent, such that air doesn't leak around the edges of
the fan.

I have one old computer case here, that I still use, and I removed
three drive bay covers, and built an aluminum bracket to hold a fan
over the three drive bays. I removed some PCI slot covers on the
back of the computer, to make room for the exhaust air. For that
computer case, I didn't have to saw up the case itself, but fitted
cooling using the available holes.

+----------------+
| +--
| Fan <--- air flows in on
| bracket <--- front of computer
| +--
| |
<--- Removed |
<--- PCI slot |
<--- plates |
+----------------+

Since my hard drive sits right next to the "Fan bracket", the
hard drive gets nice cool outside air. The hard drive is the
thing that must be kept cool - the processor can protect itself
via throttling, if it gets too hot. The processor also has the
option to turn the computer off, if the throttling does not stop
the temperature rise. But your disk drive will suffer silently,
until the day it fails and takes your data with it.

Hard drives are sensitive to temperature and humidity. If the
air is dry, the hard drive can take more temperature, than if the
air is humid. At 60% relative humidity, a modern hard drive can
only take about 35C. (This information can be found in the OEM
manual for the disk drive, on the manufacturer's web site.) If
your humidity is lower than that, then a higher temperature is
allowed. The hard drive has a "breather hole", and the humidity
in the room eventually appears inside the drive, and that is why
the environment specification for hard drives, includes the
humidity factor.

For most people, the easiest way to improve case cooling, is find
a better computer case.

For example, this computer case has two 120mm fans on the back.
The power supply fits in a bay at the bottom of the computer case.

http://images10.newegg.com/NeweggImage/productimage/11-119-092-08.jpg

There is plenty of ventilation space, as the side cover has a huge
hole in it.

http://images10.newegg.com/NeweggImage/productimage/11-119-092-06.jpg

There are thousands of computer cases to choose from, and look for
features like that, to keep the contents cool.

http://www.xbitlabs.com/misc/picture?src=/images/other/coolermaster-cmstacker/p18.jpg&1=1

"COOLER MASTER Stacker 810 RC-810-SSN1 Silver/ Black Aluminum Bezel"
http://images10.newegg.com/NeweggImage/productimage/11-119-092-09.jpg

Another way to control temperature in a computer case, is via
"zoning". There are some computer cases, that divide the internal
space into "compartments", isolating high temperature components
from low temperature components. That method can help separate the
hot CPU exhaust air, from hitting the hard drives. One consequence
of using a "zoning" approach, is the computer case is much less
roomy inside, so it is hard to fit a whole bunch of disk drives,
for example. The computer cases that Apple Computer builds, are
examples of carefully zoned designs - all fans used are low RPM,
and are speed controlled by the temperature of each zone.

http://images.apple.com/powermac/gallery/images/open20051018.jpg

HTH,
Paul

 

[kony]

Excellent and informative post, thank you! Comments and questions below...

The thermal resistance of the CNPS7000 AlCu is 0.22 to 0.29C/W.
(as stated in the papers that come in the package). With the fan
connected directly to the motherboard header and the fan getting
the full +12V, you should get the full 0.22C/W performance.
40C / 0.22C/W = 182W. The processor would have to be dissipating
182W to have a 40C temperature rise over computer case ambient
(mobo temp).

This is good news, I hope you are right!

The 3.2E processor is only 89W TDP, as stated here.

http://processorfinder.intel.com/scripts/details.asp?sSpec=SL88K\

[actually it's
http://processorfinder.intel.com/scripts/details.asp?sSpec=SL7E5 but it's
the same thing]

This means the heatsink is _not_ making good contact. Poor
contact would mean theta_R is higher than 0.22C/W . Pull the
heatsink and check the thermal grease pattern, to see if the
heatsink is making good contact.

How can I tell from the pattern whether it's making good contact? Do big
"pools" mean contact is poor?

Good contact is fairly obvious when you see the resultant
thermal compound... it will have a very thin uniform layer
where the heat spreader was and a slight bit of excess
compound squeezed out the sides (is typical, but not in
itself necessary as some people have fine-tuned their
compound application to the extent that there won't be any
excess, as the most important factor is thinnest compound
possible to create an even layer in the middle, not getting
every last mm of the spreader (at the edges) covered.

A few years back heat spreaders were even a bit concave, and
extruded heatsinks were as well and it would tend to work
better to not spread compound all the way to the edges of
the nickle-plated spreader slug, at least unless the slug
had been lapped relatively flat ahead of time. Current gen
CPU spreaders are flatter than those were though, main issue
is just not to overapply compound, rather in the middle then
let the heatsink pressure spread it out.