Radeon suck. All versions except 7000 (that we don't now for sure), they have bad OGL (so many errors), bad offload for CPU (they need more CPU performance), bad code morphing and bit manipulation (not good or many emulation instructions). Personal experience: RIFT with Wine, Core2duo SSSE3 CPU@3ghz, Radeon4670@500gflops: 15fps(low quality renderer), 18fps(hight quality renderer - low settings). With an Nvidia@500gflops its 25+fps. Nvidia loads more graphics, wile CPU is at the full on both.