Half-Life 2 being a not very demanding application, the PowerColor X800 GTO offers enough performance for playing it comfortably with enabled 4x FSAA and 16x anisotropic filtering in all resolutions. The RADEON X1600 XT and the GeForce 6800 are limited to 1280x1024 resolution in this case.
Unlike in the previous scene, the GeForce 6800 GS is not faster than the PowerColor X800 GTO in the battle scene we recorded on the d3_c17_02 map. The difference is 0.2fps. By the way, this scene is more complex than the previous one, so if you want to play Half-Life 2 on the RADEON X800 GTO with full-screen antialiasing enabled, you may want to restrain yourself to 1280x1024 resolution to have some reserve of speed.