Recently I came with the idea that my big computer is just useless. I know I was not using its entire CPU power, so I decided to take a look at CPU frequency scaling.
Last time I tried, it was a PITA, required something like a daemon, and just did not work. With recent hardware and/or kernels, it's just easy as Debian.
etch
- Look at /proc/cpuinfo to determine your CPU and the cpufreq module. If it's a Pentium, you can try p4-clockmod, powernow-k7 for AMD, or acpi-cpufreq for both. Well, if none loads, let it go, it won't work unless you get newer hardware or maybe newer kernel.
- Add this module in /etc/modules to get it loaded at boot time.
- Run apt-get install cpufrequtils
- Edit /etc/default/cpufrequtils to enable it at boot time, and specify the governor if you want. I usually use ondemande, which is just fine.
- Run /etc/init.d/cpufrequtils start
- Play with cpufreq-info and cpufreq-set as you wish.
lenny
- Run apt-get install cpufrequtils
- Edit /etc/default/cpufrequtils to enable it at boot time, and specify the governor if you want. I usually use ondemande, which is just fine.
- Run /etc/init.d/loadcpufreq start
- Run /etc/init.d/cpufrequtils start
- Play with cpufreq-info and cpufreq-set as you wish.
On my box, the 3 GHz CPUs (Core 2 Duo) are running at 2 GHz (the lower value) at 99.13% of the time. That's almost a bit less power wasted.
