We don’t think you need our comments on the results of this test: this game just runs faster on NVIDIA’s GeForce6 GPUs. They owe their high performance to the id Software engine, which takes advantage of NVIDIA's architecture and in particular, actively uses their UltraShadow technology. While ATI’s chips with their rather ineffective OpenGL driver fall behind.
The twofold advantage of the GeForce 6600 GT over the PowerColor X700 PRO is true for the “eye candy” mode, too.
It’s the same on the d3dm4 level – ATI’s RADEONs run Doom III very slowly. Only the 16-pipelined RADEON X800 XL performs like the GeForce 6600 GT, which belongs to a lower market sector.
The same goes for the “eye candy” mode with its full-screen anti-aliasing and anisotropic filtering. Let’s wait till ATI releases its new OpenGL driver?