Power saving with free Radeon (ATI) driver
From this blog
You have two options, both involve editing /etc/init.d/ati-power-save
options
gksu gedit /etc/init.d/ati-power-save
First method is called “dynpm” and the second method is called “profile” method.
dynpm method
Dynpm method is more modern and efficient but it might not work with some hardware combinations (like mine for example).
Add these lines:
#!/bin/sh
# ATI power save
echo dynpm > /sys/class/drm/card0/device/power_method
Reboot
Profile method
Power profile method is based on four power profiles you choose manually or at boot time using script like the one we are creating here. You can choose between 1. “default” 2. “auto” 3. “low” 4. “high”.
Add these lines to the file
#!/bin/sh
# ATI power save
echo profile > /sys/class/drm/card0/device/power_method
echo low > /sys/class/drm/card0/device/power_profile
Reboot
Either method
Save the script and make it executable
chmod a+x /etc/init.d/ati-power-save
See the blog for additional details.