does thermal paste degrade with time?

[ik9000]

Last year I could run Crysis Warhead on Full and CPU would run at about 40C, idle at 34C - even on hot summers days.

Same flat a year on, same machine, same game, same settings, CPU was hitting 60C last night and spitting out warnings + game started auto-pausing!

Idle seems to be up at 43C.

Had a quick fan filter clean and squirted compressed air at the cooler. It settled out at 57C

I'm wondering whether the thermal paste might be in need of a refresh or am I barking up the wrong tree?

[chuckskull]

I've never seen it and for that kind of increase it would not only have to degrade but also probably insulate instead of conduct. So, unless you're using freakishly bad thermal paste, unlikely.

Possible causes; dying fan(s), check the speeds,
The 460, when they get bunged up they start dumping a lot more heat into the case, so give that a clean if you haven't
Loose HSF, check the screws. Might be worth just going and remounting it with new thermal paste anyway.

[AndyG]

Wouldn't have thought it's the TIM, but if cleaning out the heatsinks, fans, and vents doesn't help it might be worth replacing just in case. Also, if it's an under-desk PC it might be worth checking behind the case for obstructions to the vents.

Also, last summer was cold (coldest since '00) and this one has been hot so far (hottest since '06) so that might be making a difference - it has for me, I've felt the exhaust heat from my SLI 470's for the first time ever...

[Distincthd]

Check the fan and clean the heatsink and if temps don't get reduced, replace the thermal paste and if still to no avail, get a new cpu cooler. I know it costs money but small price to pay for a bunch of hours on end of seemingly endless fun right? ^^

[PK71]

I recently removed my mates cpu heatsink to give it a clean and on his 12yr old system the thermal paste still looked fine to me.

[ekamdeep]

thermal paste gets better with time and the bond between the cpu and heatsink get better so clean your heatsink and make sure your exhaust fans are working correctly

[pastymuncher]

I have known some to dry out. That would probably affect temps. Another possible thing is if your motherboards cpu voltage is on auto, especially if using auto overclocking. Maybe the motherboard has determined that it needs to supply more voltage for a certain clockspeed.

[timcamnz]

Surely even 60C wouldn't cause standard CPU's to lockup? It's been a while but I remember thinking 75 was a limit that I had in place.

[crossy]

Last year I could run Crysis Warhead on Full and CPU would run at about 40C, idle at 34C - even on hot summers days. ...
I'm wondering whether the thermal paste might be in need of a refresh or am I barking up the wrong tree?

Any chance that the HS could have come adrift slightly? No experience with the Mega H myself (Noctua DH-14 at the mo') but I've certainly come across situations where the HS has moved. I also remember hearing that some of the older Arctic Silver pastes could separate if incorrectly stored, but in your case I think that most unlikely that separation is the cause.

Of course, if you've used the tube of "unlabelled white gunk" that came with the HS rather than a proper compound then who knows. If the case then perhaps this is a golden opportunity to whip off the HS, clean it and the cpu cap and slap on some decent HSC? AS5 is less than a tenner so surely it's a cheap "upgrade"?

[ik9000]

Any chance that the HS could have come adrift slightly? No experience with the Mega H myself (Noctua DH-14 at the mo') but I've certainly come across situations where the HS has moved. I also remember hearing that some of the older Arctic Silver pastes could separate if incorrectly stored, but in your case I think that most unlikely that separation is the cause.

Of course, if you've used the tube of "unlabelled white gunk" that came with the HS rather than a proper compound then who knows. If the case then perhaps this is a golden opportunity to whip off the HS, clean it and the cpu cap and slap on some decent HSC? AS5 is less than a tenner so surely it's a cheap "upgrade"?

It's already running with AS5. (For the record, the paste that came with the Megahalems was tested by Silent PC I think in a group test. They rated it "B" as opposed to the AS5 which went into the A+ category. Unlabelled white gunk came way down at "D" IIRC. And someone on here was posting links in another thread where some bright spark tried using mayonnaise. Don't do that. Ever.)

I'll check the cooler mountings though I'd be surprised as it's on a hefty mount with multiple sprung screw mounts that were a real git to get done-up to start with. The machine is due for a bit of a internal poke around as the front header ports keep dropping HDDs so I'll have a shifty when I next take the side off.

[fozan1072]

Yes it does. It dries out and looses the ability to pull the heat away from the CPU. That can cause your rig to over heat and shut down.

[peterb]

Yes it does. It dries out and looses the ability to pull the heat away from the CPU. That can cause your rig to over heat and shut down.

It doesn't pull heat away from the CPU - it is to fill the tiny gaps between the cooler and the CPU - in an ideal world both surfaces would be completely flat and thermal paste wouldn't be needed (which is why some overclockers lap the surfaces of the cooler and CPU.

The thermal paste needs to flow when first applied so it can fill these gaps (it also needs to be applied thinly so it doesn't form a barrier) but if it dries out after application, it doesn't matter - until the cooler is removed - and then the old stuff has to be removed and new paste applied.

[tonkins]

Even with hefty mountings the megahalems(and pretty much all the aftermarket coolers) are so damn heavy even a small jolt can move them fractionally enough to break the seal with the TIM. Most TIMs have pretty low to no adhesive quality so when they get knocked slightly the cooler/tim/cpu arent in alignment anymore and the peaks in the TIM that were in valleys on the cooler aren't anymore. Despite the PC being in a foam box a thermalright Ultra-120 I was using got knocked sufficiently to break the seal with the TIM on a car journey and the temps went up 15 degrees.

[ZaO]

I've also seen thermal paste dry out on some peoples computers. But this is only on prebuilt pc's that are like 6+ years old or something. I usually take my build apart at some point every year and give it a proper all round clean, which means reapplying the thermal paste. But if I were you I would be checking for airflow issues and cleaning dust out first, making sure fans are running correctly etc. If that doesn't do it, then it wont hurt to reapply some fresh thermal paste. But just remember to clean the cpu and heatsink of the old thermal paste properly first. Also, don't put crazy amounts on. You only need a really thin layer. As already said - it's purpose is just to fill in any scratches in the surface of the cpu and heatsink to make heat distribution better. It wouldn't even be used if those scratches didn't exist.

There are different methods people use for applying the paste, and different methods recommended by different manufacturers. I normally use Arctic Silver paste. I think what they recommend putting a small pea sized blob in the middle of the cpu, clamping the heatsink down, and then twisting it 45 degrees one way, then the other, then back to how it should be sitting. (Even though I think this makes the chances of scratching the cpu surface higher) This is the way I do it. But I also add four really tiny blobs of paste halfway inbetween each corner and the center of the cpu. I just find the coverage is more complete this way. The reason for not spreading the paste on is that you have less chance of air bubbles getting trapped in it and preventing it from doing its job properly. I also have tested different methods of applying the paste. And in my experience this way works the best. I have seen as much as 10c difference in cpu temps when I've done a good job of it. That's a very significant amount. Also make sure you store the thermal paste standing up in a fridge with the end of the tube that paste doesn't come out of at the top. This helps any air bubbles go to the back end of the tube and means less chance of them ending up in your application.

You might already know this stuff. But hope it's some help anyway

[ik9000]

agreed, TIM is only to bridge the interstices. I applied mine with a business card drawn over the mount. can't remember the rest of the details now. It was some online tutorial thing I found at the time. Think it was something like "prepare the two surfaces using the business card scrape technique (virtually nothing left on the surface) pea sized blob in the middle of the CPU (or depending where your cores are - had a nice series of pictures for suggested blob-arrangement depending on chip architecture) and then stick that chunk of metal on top and clamp the thing shut....

Case is fully de-dusted using vacuum and air duster. Confident it isn't dust build up. Though the GPU might need a bit more love... I actually have a spare I got for SLI until I realised I'd bought the wrong motherboard (cough) so I can swap it out and see what difference that makes.

I just need a weekend when I have some time. Being married really eats your free time. Suddenly your diary is full of things you haven't planned and know nothing about. :|

[MrJim]

I think it depends on the composition of the TIM. I know some types need time to 'cure', at which point it reaches its optimum thermal properties. I don't know about Arctic Silver, but I know the MX TIMs made by Arctic Cooling are supposed to be good for 8 years (or at least, that's what is says on the packet!).