http://www.semiaccurate.com/forums/s...86&postcount=4

HD 5870: +10% to +155% over GTX 285 (in 17 games, total 40 configurations), -25% to +95% compared to GTX 295 with AA/AF enabled (AA: 2x-8x, AF: 8x/16x, in 16 games)
HD 5870 CrossFireX: (2 GPU) +/-0% to +90% over GTX 295 SLI*, (3 GPU) +10% to +160% over GTX 295 SLI* (in 15 games)

HD 5850: -25% to +120% over GTX 285 (in 19 games, total 50 configurations)

And 8.66 Beta 2 Driver was used.