The highly anticipated game S.T.A.L.K.E.R. makes use of a proprietary DX9 game engine, dubbed "X-Ray" by its developers. It features an advanced DX9 renderer with Defferred Shading capabilities, which allows the engine to draw a vast amount of dynamic light sources with correct materials and light ‘feedback’. Becuase S.T.A.L.K.E.R. does not have a built-in benchmarking tool, we tested the game using FRAPS at resolutions of 1,280x1,024 and 1,600x1,1200 with the in-game anti-aliasing and anisotropic filtering options set to their maximum values, and with full dynamic lighting enabled. With We should also note that 'grass shadows' were disabled due to the further slowdowns this feature causes during gameplay.
The new GeForce 8600 GTS and GT cards' performance as they relate to the GeForce 7950 GT and Radeon X1950 Pro are better in S.T.A.L.K.E.R. than in the previous titles we tested, but none of the mainstream cards put up very fluid framerates here. We need to reiterate that we tested this game at its most taxing settings, however. With reduced image quality settings the game would no doubt perform better.
We would also like to point out the performance scaling of the 8600 GTS SLI configuration versus the CrossFire rigs. Enabling CrossFire actually reduced performance, whereas enabling SLI caused significant performance icnreases. We suspect SLI performance scaling will be better in future driver releases with this game though, based on converstations we had with representatives from NVIDIA. ATI's driver team will likely be doing some tweaking as well.