DOOM 3
Running DOOM 3 in high-quality mode is an NVIDIA benefit. Both Radeon X1800 XL 256MB cards are slower than a GeForce 6800 Ultra, a GPU from the previous generation. An average framerate of 64FPS at 1600x1200 still makes DOOM 3 playable enough, however.
Increasing the GPU workload by adding 4x antialiasing brings both 'XLs back to GeForce 6800 Ultra parity. We'd not go above 1280x1024 setting if you want smooth gameplay, though.
