Quake 4 is a relevant test as this is obviously a very popular multiplayer game. Having a low framerate while competing in a local LAN is only going to hurt your chances of winning.
Well a die shrink, less pixel power, and slower clocks aren’t going to help performance here in Quake 4. However the new X1950 Pro is able to hang with the 256MB X1900XT at 1600×1200.
More of the same while running in CrossFire, the Nvidia 7900 GT SLI system is just too much in Quake 4 for the new kid on the block.