My ATX12V on 12V2 produces 22A 12V1 22A 12V3 & 12V4 produce 25A All 12V's together give 760W I am getting a PSU upgrade anyway to fit my current case. I am hesitating between a: - Corsair TX650 - Corsair TX750 - XFX 750 W Black Edition - Thermaltake Toughpower XT 750W These all have single rails. The best choice seems Corsair or XFX according to the reviews. XFX has slightly better efficiency while Corsair has longer warranty. I still have 6 days to decide.