how to underclock AMD Phenom, set minimum CPU frequency lower than allowed

m00ny · 10-28-2013, 01:36 PM

I'd like to set the minimum frequency of my 3 CPU cores from 800MHz to i.e. 400MHz to save some power while idle.
This is not officialy supported by the CPU model "AMD Phenom(tm) II X4 B55 Processor". I can't set it (as root) in /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq under 800, it just won't be set and ignored, while 900 is possible.

Is there a way to override the limits? I know this is often done by overclocking, but that's not my interrest.

TobiSGD · 10-28-2013, 03:15 PM

You would have to change the base clock frequency, those limits are hardwired by setting fixed multiplicators.
Actually, it isn't worth the effort, the saved energy would be next to nothing, there are better places to start with energy saving.