Splinter Cell: Chaos Theory
It appears as if antialiasing is still a problem for the Radeon HD 2600 XTs. The GeCube's near-60 per cent bandwidth advantage when compared to the Sapphire HD 2600 XT is manifested in a frame-rate increase of around 15 per cent. Clearly, then, core speed, which is identical, is the main performance-limiting factor.
There's nothing much to choose between the trio in Splinter Cell: Chaos Theory, really, and the game looks good at 1280 x 1024 with anisotropic filtering and HDR applied.