How to make use of Graphics Chips Power Management features
Contents
Power Saving With A Framebuffer Console
In order to use the dynamic GPU clock-scaling similar to what X.org has, you need to use the radeonfb kernel module. You'll need to enable the CONFIG_FB_RADEON in your kernel configuration. If setup correctly you should see something like the following in your kernel log:
radeonfb: Dynamic Clock Power Management enabled
DynamicClocks in the Radeon Xorg driver
The xorg X server has support for a power saving feature from ATI called PowerPlay. Xorg calls this feature DynamicClocks. It can be enabled in the server by adding Option "DynamicClocks" "on" in the Device section in /etc/X11/xorg.conf
Section "Device" Identifier "Videocard0" Driver "radeon" VendorName "IBM Thinkpad" BoardName "ATI Radeon Mobility M9" Option "DynamicClocks" "on" EndSection
With this option enabled, the X11 server should print (/var/log/Xorg.0.log):
(**) RADEON(0): Option "DynamicClocks" "on" (II) RADEON(0): Dynamic Clock Scaling Enabled
Marketing information from ATI
How to use it
After enabling it, my first question was how do I control it? After reading about it, the answer is: you don't have to, it manages the power consumption for you.\
x.org on Debian
Because debian doesn't have X.org yet - Installing a non-intrusive X.org server on Debian.
Update: X.org has made it into Debian. See: [1]
There are also sarge backports available here or here.
deb http://people.debian.org/~nobse/xorg-x11/ sarge main