Prescott crazy hot even with all I have done

[suputnic]

I have a 2.8GHZ Prescott chip. I thoroughly cleaned the Zalman AlCU
fan, and put Arctic silver paste on the heatsink according to
instructions. I have taken off the side off the case. I have an
extractor fan too. So why is it running at 70C as I type this? The mobo
is Gigabyte 8I875. CPU fan is at 2596 RPM, the top speed I think.

 

[johns]

I don't really know, but I do know that the instructions
for applying the thermal paste are generally wrong.
You don't put it on thin and spread it. You put it in
the middle of the cpu, and kind of pile it. Put enough
to cover the chip, and spread it so that it stays
fairly thick. Then put the heatsink and fan on, and
wiggle it to make sure it is seated properly in contact
with the cpu. Then clamp it. After that, when you turn
the PC on, the heat will spread the paste thinly and
evenly. That will give good heat coupling to the heat
sink. If you spread it thin, you might as well not
use any.

johns

 

[RAID!!!]

I don't really know, but I do know that the instructions
for applying the thermal paste are generally wrong.

I've used both methods and both work equally well in my experience. Neither
is right or wrong.

The Prescott cpu does run hot but 70c is not normal. Maybe your mb sensor
is out of wack? Temp censors on mb's are rarely accurate anyway.

 

[Tomcat (Tom)]

I don't really know, but I do know that the instructions
for applying the thermal paste are generally wrong.
You don't put it on thin and spread it. You put it in
the middle of the cpu, and kind of pile it.

I always thought you were supposed to put on a tiny amount, but make
sure it covers the entire CPU evenly. It only has to fill microscopic
gaps in the contact surfaces so putting it on thickly is overkill and
can actually make it worse because tiny air bubbles form in the thick
coating.

 

[SteveH]

I always thought you were supposed to put on a tiny amount, but make
sure it covers the entire CPU evenly. It only has to fill microscopic
gaps in the contact surfaces so putting it on thickly is overkill and
can actually make it worse because tiny air bubbles form in the thick
coating.

S'ok, Johns often talks rubbish.

 

[RussellS]

I have a 2.8GHZ Prescott chip. I thoroughly cleaned the Zalman AlCU
fan, and put Arctic silver paste on the heatsink according to
instructions. I have taken off the side off the case. I have an
extractor fan too. So why is it running at 70C as I type this? The mobo
is Gigabyte 8I875. CPU fan is at 2596 RPM, the top speed I think.

-------------------------------------------------------------------------------------
This does sound like a thermal compound application problem, and/or the
heatsink isn't mounted completely. Those Prescotts do run hot, but should
be idling at around 25C less than yours, depending upon other system cooling
factors.

Reapply the Arctic Silver, first being absolutely sure to completely clean
the CPU and heatsink using 90%+ isopropyl alcohol several times with
lint-free cloth/coffee filter or similar for the last wipe or 2. For a
Prescott, then put a small amount of the Arctic Silver on the heatsink
contact surface, rubbing it good into the surface and rubbing in alternating
circular motions to get those silver microbits within the microscopic ridges
of the heatsink surface. Rub almost all of it away until just a very light
haze remains and most of the silver compound is removed by the circular
wiping.

Next, put a VERY small dab of the Arctic Silver directly on the center of
the CPU surface plate. Not too much, just a little less than the size of a
"bb". Don't spread it out, but then just mount the heatsink directly down
onto the CPU and press down. VERY slightly try to twist the heatsink a mm
or 2 in both directions once while pressing down evenly, just enough to fill
in any air gaps, then mount the heatsink to the motherboard securely as
directed by the manufacturer. Double-check that the heatsink is secured
tightly.

After finishing up and powering up your system, perform normal tasks in
somethng like 10-15 minute increments, then power off your system and let it
cool down for 15 minutes or so, then power up and repeat 3-4 times in order
for the Arctic Silver to expand/contract/fill in gaps. Cooling performance
should also improve a couple of degrees over the next several days.

Hope this helps.

Russell
http://tastycomputers.com

 

[BigJim]

I am overclocking a Prescott 3.2 to 3.5 and my idle temp is 52c with a stock
fan.

 

[DaveW]

One possibility is that your case does not have adequate case cooling fans,
and so your CPU fan is just blowing hot air around inside the case.

 

[suputnic]

Well I have pulled the side off the PC and it is reading 67C, not a big
help.

 

[suputnic]

This is exactly how I installed it.

 

[suputnic]

Thanks for this advice. I have followed these instructions except for
the initial spreading bit. The point is, I have surely done it well
enough for something else to be the cause of such a large temperature.
A CPU stress test ran the CPU 100% straight after I reassembled, but
now it is throttling quite a bit.

 

[Ed Medlin]

Well I have pulled the side off the PC and it is reading 67C, not a big
help.

I have an EM64T Prescott core I630 (3.0ghz) that gave me hell with cooling.
The stock Intel cooler was quite large, but I found that a stock replacement
HS/Fan unit made by Spire was a bit larger and quieter and did a somewhat
better job at a low price(about $12 US bought locally). That dropped my idle
temps from 58C to 50C which was a help, but my load temps were still going
to 75-80C. My Lian Li case had an exhaust fan in the top and just for grins
I disabled it and my temps dropped dramatically. It seems that the top
exhaust fan was causing a "dead air" area in the CPU socket region by
disrupting the airflow front to back. My system now idles at 48C and maxes
out under load at 65C (OC'd from 3.0ghz-3.6ghz now). This is still warm IMO,
but well within Intel's thermal specs and very stable. So, if you are sure
that your HS and thermal paste is ok, try some experimenting with your case
airflow. These CPUs run hot and you are not going to see P3 or Core2 Duo
temps with them. They don't start throttling back until about 75-78C
normally so I would try to get your load temps down under 70C maximum. Your
load temps is what is most important. Idle temps are not going to be very
low with standard air cooling with these CPUs anyway.

Ed

 

[RussellS]

Ok, if you're absolutely sure you cleaned the surfaces and applied the
thermal compound properly, and your CPU is throttling (probably indicates
70C or higher CPU temp) and removing the case panel doesn't improve temps
appreciably, then the problem is probably with the mounting of the heatsink
itself; something is hindering the heatsink contact surface from optimally
transferring heat from the CPU plate. Your system isn't going to last long
running CPU temps like that. Get a compatible replacement heatsink/fan
combo from a popular third party manufacturer like Zalman, Scythe, etc. and
try that, or take your system into a shop to have them attempt the
installation for you. A competant shop technician shouldn't let the system
leave the shop without maintaining satisfactory CPU temps.

Good luck,
Russell
http://tastycomputers.com
------------------------------------------------------------------------------------------------

 

[johns]

I always thought you were supposed to put on a tiny amount, but make
sure it covers the entire CPU evenly. It only has to fill microscopic
gaps in the contact surfaces so putting it on thickly is overkill and
can actually make it worse because tiny air bubbles form in the thick
coating.

True, but if the thin coating is cold, it will not flow
and it does not weld to the heat sink. If thicker, if
will flow and "wet" the heat sink. A thin coating will
not flow up, so the thick coating "wets" the cold
heat sink, and then spreads out to the thin coating.

johns

 

[suputnic]

Thanks for the help. I already have a Zalman fan. I will take it to a
repair shop. It has been running for well over a year now at temps over
70C, but throttling would help it survive.

 

[Marcus]

Is there a sure way of telling if a CPU is throttling. An old program I used
to have called wcpuid used to have a live clock speed reading for the CPU,
would this show up a throttle ??