Hi guys, i'm really desperate. I've read thousands of forum pages but seems nothing can solve my problem. I bought a ATI Radeon HD4870x2... well i get crap performance, 7-8 fps on Crysis no matter settings. I have a AMD Phenom 9500, 4gb of memory, my MO is N2M-SLI Deluxe and my S.O. is Vista Ultimate 64. The card works fine on same computer under XP32 (30-40frames on Cysis 1920x1200 high settings). Support tell me is a power supply issue because i have a 500W and the card require a 650. Ok but works on XP32!! So is a driver issue?? I've installed everything, official and unofficial... nothing works. Support tell me that i have to install Catalyst 8.7 but this driver not recognize the card! So only 8.8 or 8.9 beta. Nothing... Any of you have this card under Vista 64? You think that power supply is really insufficent on Vista but may be enough on XP?