It's now been two months since Half Life 2's release and much to everyone's surprise, the game was far from a GPU hog. The more powerful your graphics card, the better everything looked and the smoother everything ran, but even people with GeForce4 MXs are able to enjoy Valve's long awaited masterpiece.

Immediately upon its release we looked closely at the impacts of GPUs on Half Life 2 performance in Parts I and II of our Half Life 2 coverage. Part I focused on the performance of High End DirectX 9 class GPUs, while Part II focused on mid-range GPUs as well as the previous generation of DirectX 8 class GPUs.

The one area we had not covered up to this point was the impact of CPUs on Half Life 2 performance. In a 3D game, the CPU is responsible mainly for the physics of the environment as well as the artificial intelligence of the NPC elements of the game. There is also a good deal of graphics driver overhead that taxes the CPU, and thus with more complicated games we get higher dependencies on fast CPUs.

http://anandtech.com/cpuchipsets/showdoc.aspx?i=2330