What can we say about Counter-Strike: Source that hasn't already been said before? It is quite simply the benchmark for team-based online shooters and, four years after its release, it's still one of the most popular games in its genre. In complete contrast to Enemy Territory: Quake Wars, it focuses on small environments and incredibly intensive small-scale battles with one-shot kills the order of the day. If you want to test all elements of your first person shooter skills in one go, this is the game to do it.
We test using the 32-bit version of the game using a custom timedemo taken during a game against bots on the cs_militia map. This has a large amount of foliage, so transparency antialiasing has a significant impact on image quality and performance, and is generally one of the most graphically intensive maps available. We find a frame rate of at least 60fps is required for serious gaming as this game relies massively on quick, accurate reactions that simply can't be compromised by dropped frames.
All in-game settings are set to their maximum and we test with 0xAA 0xAF, 2xAA 4xAF, and 4xAA 8xAA. Transparency anti-aliasing is also manually turned on through the driver, though this is obviously only enabled when normal AA is being used in-game.
Counter-Strike: Source has always tended to favour ATI's cards and here this is highlighted quite starkly. By all accounts the GTX 295 should at the very least be level with the HD 4870 X2, but it consistently falls behind. However, this is such an old game now that, as with CoD4, the relative performance is a bit irrelevant because they all do so well.