Here's my situation. I have a nVidia based mobo and a ATI card (X1900XT). I want to trade my X1900XT for the new 7900gt 512mb. I want to do this for 2 reasons: #1 is for SLI support and #2 is that the 7900gt run quieter. I play quake 4, HL2, doom 3, prey, F.E.A.R., Oblivion, BF2, etc.... Is this a good descision?