I just got my MP8800 yesterday, and today installed World of Warcraft. After several hundred patches, I launched the game and was surprised by the performance. At default settings (many sliders set at low) I was getting 60fps, and when I maxed them out, a feat that the MacPro (to say nothing of the 8800gt)should be able to do without breaking a sweat. I am now getting between 14-15 fps. What could be the cause of this? I'm running 10.5.2, and I installed the Graphics Update. MacPro 2.8 Octo Nvidia 8800GT 6 GB RAM
WoW used to run on my gf's single proc 1.25 Ghz G4 with a Radeon 9000. Certainly not with all settings turned up, but it ran pretty well. The point is that this is an old game now, and it's extremely well optimized. The OP's system should be able to get 60 fps with every setting maxed, easily. IMO there's something wrong here. That said, I don't know what it could be. Maybe ask other mac pro owners what their settings are and what fps they get?