Tuesday, June 2, 2009

how to - manually change the CPU(s) frequency in Debian

- make sure you enable loadcpufreq, cpufreqd, cpufrequtils "services" to start on boot; without reboot :
/etc/init.d/loadcpufreq start
/etc/init.d/cpufreqd start
/etc/init.d/cpufrequtils start
-
edit /etc/cpufreqd.conf
before (Debian default) :
[General]
pidfile=/var/run/cpufreqd.pid
poll_interval=2
verbosity=4
#enable_remote=1
#remote_group=root
[/General]
after :
[General]
pidfile=/var/run/cpufreqd.pid
poll_interval=2
verbosity=4
enable_remote=1
remote_group=root
[/General]

- restart cpufreqd (to reload the configuration)
/etc/init.d/cpufreqd restart
- to list available options :
cpufreqd-get
- to select/set a specific profile :
usage: cpufreqd-set [manual | dynamic | ]
example :
cpufreqd-set manual; cpufreqd-set 3
(activate the 3rd profile on your config)

Feel free to customize your profiles (/etc/cpufreqd.conf). Hints :
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors

Enjoy !