Normal rate of CPU temperature fluctuation

Question

Currently my CPU temperature as measured by lm-sensors increases by 1-2 C upto 4-5 C when I start a new process - like a video, music, etc. The change takes place in less than a second. Is this normal or should the change be happening more slowly?

If it is indeed happening too rapidly, what could be the likely causes?

I'm running Ubuntu 10.04 with Core i5 430M.

Thanks

Edit: I should add that these are temperatures from an HP laptop (dm4t).

Answer 1

Fast changes in CPU temperature are normal. 4-5C is perfectly fine for big load tasks like what you describe. The reason it gets hot is that the CPU is moving from a low power state to a full power state in order to deal with the computational load. The added power means the CPU resists off more power as heat, thus the increase. So long as full load temps don't exceed unsafe values, you're fine.