Dumb cooling question

[leitec]

I decided to replace the thermal compound on a few of my PowerMacs lately. I noticed on one of them in particular (Digital Audio G4, DP/533) the heatsink is noticeably hotter (not too hot; it's warm to the touch but not uncomfortable). Since I have no way to tell if the processor itself is running cooler (no thermal sensor as far as I can see), is this expected behavior? I kinda figure the thermal conductivity is better, so the heatsink gets more of the heat from the processors--is that bogus reasoning?

I hadn't applied compound in a really long time and am not sure I've been doing it correctly, either too thin or too thick. The compound is Arctic Silver Alumina, since it had the shortest curing time out of the ones they had at Micro Center. The system is rock-solid but I am concerned about long-term damage.

 

[uniserver]

just clean off both surfaces,,, and smear a light/even amount on the cpu. You don't want any gooping out of the sides. its wasteful. and that stuff is conductive.

 

[leitec]

Yeah, I cleaned the surfaces really well. I bought a 2-step cleaning kit as well that left things very clean. No dust or lint was visible.

 

[beachycove]

I kinda figure the thermal conductivity is better, so the heatsink gets more of the heat from the processors--is that bogus reasoning?

No, since the basic idea in cpu cooling is essentially to extract heat/ energy from where you don't want it to where you do. In this case you want it in the heatsink for dissipation through the circulation of air.

Warm to the touch is good. Warmer to the touch than before is better. Anyway, the machine will let you know if it is unhappy.

 

[leitec]

Thanks, that's good to hear.