3D Mark
In lower resolution benchmarks, we can see that ATI has a lead in 3D Mark 05, however in the previous versions of this benchmark, Gainward's 6800 Ultra has a slight edge. At higher resolutions, the X850 takes the lead without doubt, leaving both nVidia cards behind.
Aquamark 3
Aquamark 3 shows a similar situation to 3D Mark - the 6800 Ultra has the lead in the lower resolution tests, however as soon as the details are cranked up, Sapphire's X850XT PE takes the lead once again. It is also worth noting that the FX 5800 is about half as fast as the Radeon on default settings. Interestingly, when antialiasing and anisotropic filtering is turned on, the Radeon shows only minimal changes in score.