# Pentium M (Centrino) and Dynamic CPU Speed Scaling

## ee99ee2

Pentium M CPUs, at least under Windows, scale up and down with the amount of load they are under to save power. In other words, when idle, they'll scale way down to something like 200MHz (or less?), but bounce back up to 1.8GHz (or whatever) when the demand is high. Is this handled by the hardware, or the OS? I need to make sure this will work in Linux, and if it's handled by the OS I suppose I need to find how to how get the kernel to do what Windows does...

So, is the CPU frequency scaling something the kernel does or the hardware? If kernel, how?

-ee99ee

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## ToeiRei

you might want to have a look at speedfreqd and simmilar. There is a good hint in the gentoo-wiki.com Acer 803 install-Howto

Rei

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## rmh3093

or try the the ondemand governor and the cpufreq userland scrips make changing things easy

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