I was just messing about with my Linux-Mint KDE (Kubuntu 11.10) install. I've got KDE 4.8.2 installed from the backports. Running on my dual core 2.67Ghz Core 2 Duo laptop (which has CPU frequency steps of 800Mhz, 1600Mhz, 2130Mhz and 2670Mhz).
Anyway I've tried to add some simple scripts to my power profiles (basically these change the upper frequency limit for CPU scaling, for each core, with the on-demand
/usr/local/sbin/ $ ls -Ahl
-rwxr-xr-x 1 root root 85 2012-04-17 21:52 cpufreq_highperformance.sh
-rwxr-xr-x 1 root root 82 2012-04-17 21:51 cpufreq_lowperformance.sh
-rwxr-xr-x 1 root root 82 2012-04-17 21:52 cpufreq_mediumperformance.sh
/usr/local/sbin/ $ cat cpufreq_lowperformance.sh
sudo /usr/bin/cpufreq-set -c 0 -u 1.6Ghz
sudo /usr/bin/cpufreq-set -c 1 -u 1.6Ghz
Following the ARCH wiki
I've carefully added my user to a custom sudor's file to ensure that I can run /usr/bin/cpufreq-set
with sudo - without needing a password.
On the command line I can type:
which works - no sudo
However adding this command to the script run box in KDE
/ System Settings
/ Power Management
/ Energy Saving Settings
/ On AC Power
& On Battery Power
does nothing very much at all. The cpufreq-info
command shows the same upper CPU frequency (for each core) as before. The rest of the profile settings are loaded and I can see the tray notification for the change from AC power to battery...