The Open-Source Linux Graphics Card Showdown
When running Doom 3 at 1920 x 1080 with high quality visuals, the Radeon HD 5750/6450/6570/6770 graphics cards were faster on the R600 Gallium3D driver. The GeForce 9800GT was running at around the same speed as the Ivy Bridge graphics core with the Nouveau driver.
With the slow Ivy Bridge results on Mesa 8.1-devel for Doom 3, it also ended up losing out on performance-per-Watt to the higher-end Radeon graphics cards, except when looking at the Radeon HD 4670 and the NVIDIA cards: GeForce 9500GT, GeForce 9800GT, and GeForce GT 220.
The most power-hungry card was the Radeon HD 6770 topping out at 130 Watts -- 71% more power use than the Ivy Bridge graphics.