We have a pretty beefy DVR I use at work for image acquisition that has started overheating frequently. Overheating meaning the CPU begins to throttle down and an audible alarm goes off. Frequently being anytime the CPU becomes even partially loaded down.

I have tried removing the back panel on the case and even blowing an air gun over the processor to see if airflow was an issue. This helped a little but it still overheated in under a minute of a processor load being applied. The temperature swing reported on the processor is from ~60C at idle to 88C at throttling/alarm.

The machine is similar to the one pictured here:



The processor is an intel Xeon 5160. It already has a copper heat sink and a fan mounted to it.

MY QUESTIONS ARE:
- Is my assumption correct that since I can bring the system temperature down pretty far and the CPU overheats very quickly, that the issue must be the heat dissipation of the processor?
- How likely is it that freight transport or jarring activity would damage the heat dissipation of the CPU? The heat sink and fan are screwed down on top of the Xeon.
- How likely is it that whatever thermal compound that has been applied has simply degraded?
- How hard/risky is it to remove the heatsink and reapply it?

6/3/2010 3:49:37 PM

If you have some thermal paste its a very simple task to remove and reseat the heatsink.

Unscrew it, pop it off, clean the old paste off of the proc and heatsink, apply small amount of paste and spread it thinly on the proc, reseat and rescrew heatsink.

[Edited on June 3, 2010 at 3:59 PM. Reason : a]

6/3/2010 3:58:09 PM

^ Agreed to everything he says.

Yes also to answer you, moving it a lot will probably have loosened the heatsink.

Google how to clean/replace thermal paste. Theres a way to do it, not hard at all.

Also look into a program called Hardware Monitor (free), to monitor your temps.

Lastly, make sure all your fans are working. A dead or slow fan will wreak havoc on temps.

6/3/2010 6:09:30 PM

well you either increase air flow, change the HS, or raise your CPUs TJ Max

6/3/2010 7:19:53 PM

Thanks for each of the replies.

All of the fans, 8 total if I remember correctly, were rotating correctly.

I will get some thermal paste and reseat the heatsink. Hopefully the heat issues are from throwing the machine around and replacing the thermal paste will fix it.

BlackDog, how risky would it be to raise TJ Max? Is there some standard rule of thumb for how much you can push it?

6/3/2010 8:32:11 PM

Messing with TJ max is not a good idea. Its there for a reason. Mostly to make sure you dont melt your CPU.

6/3/2010 9:12:02 PM

Quote :

"Messing with TJ max is not a good idea. "

6/4/2010 9:19:25 AM

I wouldn't raise your TJ Max higher than 85C, it is a safety feature.

But anyone who says changing it is a bad idea must also agree OCing is a bad idea.

Which brings me to my next piece of advice, you could underclock your CPU.

6/8/2010 1:52:25 PM

I finally got approval today from our environmental safety department to order some AS5 .

When it arrives, I will try reseating the heatsink and hope that will take care of the problem.

6/8/2010 2:17:05 PM

hahaha. probably would have been faster to find some local store and spend the $5 or whatever yourself.

6/8/2010 2:54:09 PM

Well the AS5 didn't arrive from our "approved vendor" until about two weeks ago (yay corporate ineffiencies). I just had an opportunity to reapply the paste and it appears to have done the trick.

Instead of hitting TJ Max and throttling the CPU after around 30 seconds of max processor load, I can load the processor down for 30 minutes and still have about 15 C of head room.

When I took the heat sink off, it appears that someone took a super soaker of paste to the interface.

Thanks for the advice.

7/26/2010 12:18:38 PM

Great job! AS5 is still the only way to go.

7/26/2010 12:32:45 PM