The best place to start would probably be AnandTech's video section
, where they have graphic card reviews, articles comparing and discussing specific technologies, comparison between different makers, test on video processing in graphics cards and long articles about how different graphics cards do in specific games.
Another mention I could make is GPU-Z
, which is a small program which tells you a lot about the graphic card in your system.
Edited by Mr Alpha, 11 February 2008 - 07:38 AM.