The fglrx driver is able to throttle the internal frequency of the gfx card. To see the available modes use:
The setting can be changed with:
For my t60p, aticonfig –set-powerstate=1 saves about 5W.
Another device that can be set to another powersave mode is the wireless device:
iwpriv eth1 get_power
shows the current setting, and
iwpriv eth1 set_power 7
sets it into „BATTERY“ mode.