Is my CPU temperature normal?

Question

On my Lenovo T400 laptop, the CPU temperature is mid 40 Celsius under Ubuntu 10.10 and mid 30 Celsius under Windows 7 when the laptop just starts up.

I was wondering if the temperatures are normal, excellent or bad? Why there is such a big difference between Windows 7 and Ubuntu 10.10?

Thanks!

Answer 1

If your machine hasn't frozen, it's still fine. Intel CPUs can operate safely at very high temperatures (another thread on this site had one i7 running at over 90 degrees Celsius).

Modern CPUs will shut down if they get too hot, hence my comment about freezing.

For your specific question, the discrepancy could be a result of different tools being used to monitor the sensors in the different operating systems, or different CPU stepping under power saving options, as Martheen has noted.

Answer 2

How do you measure them? By physically put a thermometer or from reading from a software? If software, from CPU, GPU, chipset or harddrive? Most likely, it's because some CPU power saving features is not called by Ubuntu. Or, it could be because the GPU driver in Ubuntu is not really that optimized for power saving.