I have been looking recently for a way to enable Cool’n'Quiet functionality in Debian. To my surprise it wasn’t supported per default (at least in my case). I’ve installed cpufreq-info and cpufreqd (though powernowd should also do fine), but it was complaining about missing kernel support and no governors. I found a really nice How-To for Debian so rewriting it doesn’t make much sense.

The only thing one has to adapt is applying the settings to all cores (/sys/devices/system/cpu/cpuX/cpufreq/scaling_governor).

My AMD Athlon 4450e is now working fine with powernow_k8 module and cpufreq_ondemand governor (without cpufreqd) as you can see from the cpufreq-info command:

analyzing CPU 0:
driver: powernow-k8
CPUs which need to switch frequency at the same time: 0 1
hardware limits: 1000 MHz – 2.30 GHz
available frequency steps: 2.30 GHz, 2.20 GHz, 2.00 GHz, 1.80 GHz, 1000 MHz
available cpufreq governors: userspace, powersave, conservative, ondemand, performance
current policy: frequency should be within 1000 MHz and 2.30 GHz.
The governor “ondemand” may decide which speed to use
within this range.
current CPU frequency is 1000 MHz (asserted by call to hardware).
cpufreq stats: 2.30 GHz:50.00%, 2.20 GHz:0.09%, 2.00 GHz:0.14%, 1.80 GHz:0.54%, 1000 MHz:49.23%  (159)

The same goes for CPU 1. Here I had some background compilation job, normally 1000 MHz is near 90%.

If you want more details – read about CPU throttling in Linux. And just make sure it’s enabled in BIOS settings.