In all tests across the board from 2D to 3D, the Catalyst Linux driver was the definite performance winner compared to the open-source Radeon Gallium3D stack for the A8-3870K with Radeon HD 6550D graphics. But perhaps the open-source driver is more power efficient? Not quite.
When looking at the power consumption when running OpenArena, the A8-3870K system was going through 78 Watts when running the Catalyst driver while it was only 64 Watts with the open-source stack. However, if looking at the per-Watt efficiency of the Gallium3D driver, it is very disappointing:
While the power consumption was lower with the Gallium3D driver, on a per-Watt basis the Catalyst driver is 4.68x more efficient than the open-source code.
The newer OpenArena 0.8.8 had similar results: the Gallium3D driver was going through 20 Watts less except the performance-per-Watt power efficiency when using Catalyst was 80% better.