I wanna buy a new PC and I'm aware that PCI-E is the best. I've looked into the X-800, the X-850, and the 6800 (not GT or anything, just plain). I can afford the 6800 PC, but how much slower is it than the X-850 and 800, or even than the GT vers? Can a 6800 run lost coast and some next gen games like UT 2007? If not, than wtf can?