Phoronix: X.Org ATI Driver Supports New Power Options

Besides seeing 3D acceleration for their hardware in an open-source driver, one of the other leading requests from ATI Radeon customers has been to see improved power management within the ATI X.Org driver stack. There is Dynamic Clocks support and some other power management capabilities, along with some more innovative ways, but ATI's PowerPlay is not fully implemented in the open-source stack...

http://www.phoronix.com/vr.php?view=NzIwNg