CPU Frequency scaling / Centrino
The required package (cpufrequtils) is installed by default if you selected "Laptop" package-set during installation.
First, you need to make sure the corresponding modules are loaded by default at boot time.
/etc/modules # Add the following lines to prepare cpu scaling speedstep-centrino # or add... # acpi-cpufreq # ...instead of speedstep-centrino cpufreq_stats cpufreq_ondemand cpufreq_conservative cpufreq_powersave
Note that speedstep-centrino is deprecated as of kernel 2.6.20. Use kernel modue acpi-cpufreq instead.
Next, put the following in /etc/default/cpufrequtils, which may have to create first, if it doesn't exist.
/etc/default/cpufrequtils #Change Add this line to configure CPUs on bootup ENABLE="true" GOVERNOR="ondemand" MAX_SPEED=0 MIN_SPEED=0
if you don't want to reboot, then modprobe the above modules and run:
invoke-rc.d cpufrequtils restart
Making sure it worked
To make sure it worked, you can issue the command cpufreq-info to find out about the current governor and speed of your CPU(s).