CPU heats and cools very quickly...

[tomstevens26]

No, this isn't going to be another thread about CPU temps but rather how quickly my CPU heats up and cools down. Last Friday, I built my new system using an Intel C2D E6400 on a Giga 965P-DS3 (full system details here) using the stock HSF. Got everything installed, everything runs great. Decided to give Prime95 a try (ran 2 instances to tax both cores) and this is where I noticed something that seems odd - the CPU heats up and cools down very fast.

For example, the CPU sits idle around 37C (using Easy Tune 5), with the fan RPMs around 950. I can start both instances of Prime, and within 10 seconds or so, the CPU temp hits 61/62C (fan RPMs around 1500) and stays there. Seems a little toasty, but I've ran Prime95 overnight with no problems. The minute I stop the test, the temp drops from 61/62 back to around its idle temp in the high 30s again, within a few seconds. I've ran 6-8+ hours sessions of WoW, FEAR, and HL2 with no problems. Ran a 3DMark2006 demo loop for hours with no problems. No lock ups, no freezes, no reboots....everything runs smooth as can be so the high temp doesn't seem to be an issue.

I guess my question is is this rapid heating/cooling normal for a C2D? I've never seen a CPU do this. Everything I've ever built and watched the temps generated both a slow rise to its max temp, and a slow drop back to its idle temp, at least over the course of a minute or two...not the 10 or so seconds I'm watching now. Any ideas?

Tom

 

[TomKazansky]

My a64 939 does that too! : omghi2u : amazing!!!!!!!1111ONE.

/sarcasm

 

[Operandi]

Some of the Core2 CPUs have a slightly concave heatspreader resulting in poor contact with the heatsink. That might account for quick rise and fall of the CPU temp.

 

[tomstevens26]

Originally posted by: Operandi
Some of the Core2 CPUs have a slightly concave heatspreader resulting in poor contact with the heatsink. That might account for quick rise and fall of the CPU temp.

Yeah, my first thought when I noticed the temp jump like that was the HSF. I would expect that sort of behavior in the quick rise of the temp....but when I saw it cool back to idle temps just as quick that confused the heck out of me. I would think a flawed heatsink making a poor connection wouldn't contribute to the rapid cooling, if anything, it would hinder it, but I don't know.

 

[tomstevens26]

Originally posted by: TomKazansky
My a64 939 does that too! : omghi2u : amazing!!!!!!!1111ONE.

/sarcasm

Not real sure in the point of that reply....but if it makes you happy...

 

[Operandi]

Originally posted by: tomstevens26

Originally posted by: Operandi
Some of the Core2 CPUs have a slightly concave heatspreader resulting in poor contact with the heatsink. That might account for quick rise and fall of the CPU temp.

Yeah, my first thought when I noticed the temp jump like that was the HSF. I would expect that sort of behavior in the quick rise of the temp....but when I saw it cool back to idle temps just as quick that confused the heck out of me. I would think a flawed heatsink making a poor connection wouldn't contribute to the rapid cooling, if anything, it would hinder it, but I don't know.

Yeah, I'm not sure as I haven't built a Core2 system yet. Maybe try the CPU or Case & Cooling forums if you don't get a better answer here.

 

[ViviTheMage]

i lovers my cooling setup!

zalman all of the way.