I'm building a gaming system next month after I see Ge-Force 7800 and Radeon 520 benchmarks. The graphic intensive games I play are Doom III, FarCry, Painkiller, and soon Battlefield 2 and Half-Life 2. I've seen 6800 GT is better for these games than Radeon X800 XL (except HL2, which a 6800 GT...