Radeon DPM Is Fantastic For Power Use, Thermal Performance
Furmark -- a demanding OpenGL 3.x tech demo/benchmark -- furthers confirms that for the high-end Radeon HD 6870 the performance is slightly lower when dynamic power management is enabled although the HD 6770 and HD 4890 saw their frame-rates unchanged.
The Furmark numbers continue to show great improvements out of Radeon Dynamic Power Management.