I seem to be having a different temp. problem than what I've seen posted here before. My CPU seems to keep rising in average temp, gradually over a few months. When I first built the PC, it was running at about 40C on average under no load. It slowly kept running hotter and hotter on average though over the next few months, until when it reached 54C I re-applied the HSF and it went back down to 40C. Now, 3 months later, I'm back at about 67C again. The CPU is a stock XP2500+ Barton with the included HSF, arctic silver 5, and more than enough case fans for good airflow. I was hoping to get some ideas before I went and tore my PC apart.
Also - if the heatsink surface became scratched, how detrimental to heat transfer would that be? I noticed there are a few miniscule notches on it, barely even what I would call a scrape, so when I applied arctic silver I made sure to rub it in good to fill any holes. Would this be enough to make my CPU run so hot?
Such small scratches has no influence on the heat transfer. The only reason I can think of is that you use too much thermal compound. Excessive amount vill create a barrier between the CPU and HSF that graduatly dries out. You only need to apply enough compound to fill up any scratches. The smoother the surfaces are the less compund you need. Only apply a very thin layer. If you don't apply enough, it will show up immediatly with too high temperatures.
Also, check out whatever mechanics, springs etc. that holds the HSF. The HSF should apply a firm pressure to the CPU. Usually this pressure is enough to squeeze out any excessive thermal compound. But if you really use too much or the pressure is too weak, this may not happen.
<i><b>Engineering is the fine art of making what you want from things you can get</b></i>
Thanks guys, problem is that I'm sure I put the thermal compound on properly last time - I read tons on proper procedures to apply it and followed them carefully. Very thin layer on the CPU die and also rubbed some into the heatsink to smooth it out. I was talking to a guy yesterday who told me with his AMD he re-applies his thermal compound every 3 months - I'd never heard of this before, is it really necessary? Maybe that's my problem.
actually, thermal paste needs to "bond", and if you check out arctic silver's site you'll see that they say that there is a certain number of hours of use that are required for optimal bonding and thermal transfer