Hi, I was reading around the forums to find the amperage that the 5770 requires and it seems that a 30A - 40A +12v is required to run this card. But I was wondering if any one has been able to run it w/o meeting the amperage requirements, because my OCZ ModxStream 600W only has 25A on each of its +12v rails.
Its the combined 12v rating that you're looking for, and I would suspect that with 2x25A max rails your combined 12v output will be about 40-45A. A 5770 is only spec'ed for about 110w peak draw. 110/12 = 9.2A - and they never use this much in the real world anyway. The 30-40A is a total system rating and basically covers the manufacturer for you putting one in a overclocked quad core system with about 80 HDDs and a million fans, or one with a cheap PSU.
Bottom line is OCZs are fairly good and you can run a 5770 easily with that PSU - you could crossfire 2 of them even.