Next we’ll be running the Source Engine Stress Test with 4X AA and 8X AF enabled.

Once again the ATI Radeon X800 XT Platinum Edition comes out on top, running between 20-30 FPS faster than the NVIDIA GeForce 6800 Ultra. The same is true with the R420 and NV40 $ 400 cards, with the X800 Pro running around 12 FPS faster than the GeForce 6800 GT.

However, the tides turn for ATI’s R360 and R350 cards in our 4X AA and 8X AF tests. NVIDIA’s GeForce FX 5950 Ultra actually runs around 5 FPS faster than the Radeon 9800 XT in this series of tests.