Bjorn3D doing some testing of the latest game from Valve with Left4Dead GTX-280 SLI vs 4870 1GB Crossfire:

Valve decided to go with DirectX 9 when they coded Left 4 Dead, and making that choice and coding it in a highly efficient manner produces fantastic FPS results with both the Single EVGA GTX-280 and Diamond 4870 1 GB. When you move to SLI and Crossfire you see some improvement, but it's not really an improvement that's going to make it any better for the human eye. The game itself is definitely the best FPS horror game we've seen in a very long time and it's shown that it will play equally well on both ATI and Nvidia high end GPU's. We'd suspect that it will run just fine on mid-range GPU's like the 4850 and GTX-260.

We're hoping that this is going to be a trend among game developers, games that will run efficiently with high FPS on a wide range of GPU's and not requiring us to spend big bucks on a new GPU just to play it. DirectX 10, while providing a goodly amount of eye candy, just seems to kill the GPU's when it comes to playable frame rates. With any luck, DirectX 11 will be better optimized, but what we'd really like to see is more games that run with high FPS. It gets a little old having to upgrade GPU's every year because programmers can't take the time to optimize code, or just don't care that it takes a $500 dollar GPU just to play it.

Game play is fast paced if you want it to be, or you can take a slower pace and methodically wipe out every Zombie you see. At least until the horde comes calling. Then, it's time for some serious spray and pray. Which GPU is better for this game? Both do well enough that there's nothing to complain about and we're not rating them in this review. We're rating the game itself.