Performance under Windows Vista was tested with Lost Planet, World in Conflict, Crysis and BioShock. The 169.04 beta driver was used, which happened to lack support for the 1680x1050 resolution. This was quickly remedied by using RivaTuner to define a 1680x1050 resolution.
Note that in this series of tests, performance was not compared to the GeForce 8800 GTX. Instead, the MSI NX8800GTX was used to test the DirectX 9 and DirectX 10 code paths in Lost Planet and the impact of DirectX 10 rendering in World in Conflict.
Lost Planet Performance
World in Conflict Performance
Crysis raises the graphics bar a couple of notches and begs for a GeForce 8800 GT/GTS/GX/Ultra SLI configuration. Note that SLI is not properly supported in the demo version of Crysis.