Benchmarks: Unreal Tournament 3
With AA/AF disabled in Unreal Tournament 3 the Radeon HD 4870 was able to match the performance of the GeForce GTX 260, while the GeForce GTX 280 was 14% faster at 1920x1200. The Radeon HD 4850 was approximately 20% slower than the GeForce GTX 260.
Turning on AA/AF quality settings had a serious impact on performance, reducing the average frame rate of the Radeon HD 4850 to 56fps at 1920x1200.
With these settings the Radeon HD 4800 series cards did not fair all that well, though the Radeon HD 4870 was just 8% slower than the GeForce GTX 260.