Hey guys, I got told that it is possible to run a 8800GT alongside a 5850 for say PhysX, was just wandering if their are any guides out their which can help me or anyone to tell me what to do because I have a feeling I will muck something up if I give it a try, I tried Google but got no results so I thought I'd make a post here, thanks all for your help
Please remember that PhysX is only usable in few games, and it's highly recommended to disable your nVidia card when not playing games, as an 8800GT does use quite a bit of power, and it's wasted when not in use.
An 8800GT uses around 95Watts I believe, an an HD5850 uses 153. Assume 250Watts for the cards, a good 130 for your CPU, 70W for peripherals (MOBO/RAM/HDD etc..), and you can estime you'd need 450Watts. You should be just fine.
The thing to watch is your 12v rails though. You'll need a minimum of 40A on a single 12v, or about 4 rails with about 13A each.