Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have recently installed a new heat sink & fan combination on my Core 2 Quad since my CPU was hitting about 70C under load. This has managed reduce temperatures while running Prime95 to about 54C, which I'm taking as a win (this is ~30 minutes after fitting).

I'm a little confused though. The temperature readings given above are for CORE temperatures, but HWMonitor is showing a 5th "CPU" temperature (4 temperatures being the individual core temps) which is showing 21C idle, when idle temperatures for the cores vary between 37C and 42C.

I guess there are two questions here:

  1. Are my CPU/Core temperatures decent, and is it safe to overclock when these are stock clock temperatures?
  2. I gather that the maximum safe operating temperature for a C2Q is ~70C, so which temperature should I measure against, the core temperatures (which are higher), or the CPU temperature reading?
share|improve this question
The CPU temperature is the actual temperature of the whole CPU as measured (usually) from underneath it by a sensor on the motherboard. – Majenko Mar 19 '11 at 23:56
Which particular CPU do you have? 70 degrees sounds low for a maximum. – user3463 Mar 20 '11 at 5:35
@Randolph Potter - Core 2 Quad Q9450 Revision C1. – Karl Nicoll Mar 20 '11 at 19:13
up vote 1 down vote accepted

From my understanding 70C is maximum stable temp which you don't want to be near on a regular basis it will kill the chip faster... keeping it around 60C-65C is safe. Read this for more detail use CPUz to get the information about your cpu to compare to the posters finding... i.e. the processor model/stepping

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.