Graphics performance

With higher core and memory clock speeds, it's no surprise to see the OC2 turn in better 3D performances than the other cards. You're unlikely to notice a difference of three frames per second in a game like F.E.A.R., though.

Overclocking
The handy automatic overclocking utility built into Nvidia's graphics drivers and then relocated to its nTune system utility doesn't seem to be working properly with the GeForce 8600 or 8500 series, so we had to kick it old-school with manual slider manipulation and loads of trial-and-error testing. In order to qualify as stable, each of our overclocked configurations had to loop successfully through three iterations of 3DMark's Shader Model 3.0 tests at 1280x1024 with 4X antialiasing and 16X aniso, and then endure ten minutes of Oblivion at maximum detail levels.

We managed to hit 796MHz core and 1151MHz memory clock speeds with the BFG GeForce 8600 GTS OC2, which is higher than we've been able to overclock any other GTS card. However, as is always the case with overclocking, it's hard to draw definitive conclusions based on the stable clock speeds of a single sample. Your mileage may vary.

Here's how the overclocked OC2 stacks up against the other cards pushed to their limits.

Again, the OC2 comes out ahead, but by narrower margins, as expected. The gap in clock speed between the OC2 and other cards is actually smaller when they're all overclocked than when at stock speeds.