Check contact betwen CPU and Heatsink

Jackpine

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Apr 25, 2006
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I have come across many topics related to high cpu temperatures, where the advice included something along the lines of: "Check to make sure that there is good contact between the cpu and the heatsink."

On the face of it, this is good advice because good, i.e., sufficient, contact area is crucial to maximize the heat transfer rate between the cpu and the heatsink. However, I have found myself wondering just exactly how this is done. Short of ensuring that that the heatsink is properly mounted on the motherboard, what else can a person do? I suppose you can also check that the cpu is properly installed and locked in place. I am not sure what else can be done. (Removing the heatsink and examining the pattern the thermal paste makes will give some indication of the contact area that was present, but you are then left with the same problem when reinstalling it.)

Are there any other methods/techniques out there?
 
So, aside from advising to check that there is good contact between the cpu and the heatsink, how do people actually do this?
 
So, aside from advising to check that there is good contact between the cpu and the heatsink, how do people actually do this?

The non-intrusive way is to monitor your load temps and compare your results to similar systems operating at the same room temperature.

The intrusive way is to remove the HSF and look at the spread pattern of the thermal compound and see if you have any "dry" spots.

Obviously, no need to remove the HSF and re-apply the thermal compound if your temps are within an acceptable range.
 
I'd like to know.

I've got an IDEQ 220K that is running hot, and I noticed that if I push down on the heatsink, it cools off about 4 degrees in a few seconds. So it must not be making particularly good contact. But how do I fix it?
 
Sometimes if you swap chips out without resetting your BIOS it can raise temps as much as 15 degrees C. Don't ask me why, but it has happened before, and it's good to take care of that and rule out all possibilities. Man that word has an awful lot of i's in it.
 
Sounds like the heatsink is not making good contact. Did you check the mounting to make sure it is providing the required pressure on the CPU to make good contact? So long as it sits properly, it should work fine. 4 degrees seems to suggest slight mistfit somewhere, but it could also hint at a bigger problem, make sure nothing is between the HSF and CPU, I have a friend who tore out the transparent sticker that protects most of todays heatsink but he missed a tiny bit that is still stuck on it. That gave him like abnormal temps 55 celsius over for 6 months before he realised it in a CPU swap.
 
There are two main things to look for. First off, did the retention mechanism fully engage? It's tough to explain, but if it didn't feel right, it probably isn't.
The second is a little easier. Make sure the chip is parallel to the motherboard. If you are not getting good contact, it is probable that one side will be noticeably further away from the motherboard.