Switching over to the Qfusion-powered Warsow game, the open-source ATI driver differences between the classic Mesa and Gallium3D drivers were negligible. The Radeon HD 2900XT graphics card could not even handle running this open-source game with either driver at a frame-rate above 30 FPS while the Catalyst driver pushed the frame-rate for this R600 graphics card to nearly 200 FPS.
The Catalyst driver performance actually improved when running Warsow at 1920 x 1080 versus 1024 x 768 and the open-source driver performance stayed about the same, but still the classic Mesa and Gallium3D performance was disappointing with these ATI Radeon graphics cards. One item worth noting for Warsow is that the Radeon X1950PRO performance was far better than any of the Radeon HD 2000/3000/4000/5000 graphics cards. The Radeon X1950PRO uses the "R300c" and "R300g" open-source drivers where as the rest use the "R600c" and "R600g" respectively. These results show that for Warsow at least the R300 era drivers are in much better shape with its frame-rates being nearly twice as high while using older ATI hardware.