What is the lowest frequency a core i5-460M can safely operate at?

Question

While comparing the behavior of my new laptop(a toshiba portege r705) running under Ubuntu (10.10 64 bit with kernel 2.6.35) and Windows 7 I noticed that in Ubuntu it

1) Ran hotter

2) Seemed to have worse battery life.

Looking more carefully it seems that in Ubuntu the minimum frequency the processor runs at (a core i5-460M) is 1200MhZ while in Win 7 CPU-Z was giving lower frequencies during idle times. Running cpufreq-info in Ubuntu gave the lowest possible frequency as 1200MhZ (which was also the lowest supported by hardware).

My question is whether this is the correct frequency, an if not whether it can be made lower. Note that I'm not super familiar with linux but much prefer it to Windows (I used to own a Mac).

Answer 1

This is the minimum clock rate under normal operation. Unless the clock multiplier is unlocked (normally needed for overclocking, but also for underclocking), which is not the case with the Core i5-460M, you cannot manually lower the clock rate below 1200 MHz.