Is it enough

[Avalanche]

I know it's not highly rated, but would an Ultra X-finity 600W Dual Rail PSU work for a system with an 8800GT SLi setup? THose are the cards I'm stepping up to and I can upgrade the PSU if need be, but I'd rather spend my tax refund on a new monitor

Here are the rest of my specs, including current video cards:

XFX 680i LT SLi Motherboard
Core 2 Quad Q6600 @ 3.2 GHz
2x EVGA 8600GTS Superclocked 256 DDR3
4 GB Corsair (2xTWIN2X2048-6400C5DHX) DDR2 RAM
Ultra ATX 600W PSU w/dual 12V rails
Western Digital Caviar 500GB SATA HD
3 LED Fans, 3 Case Fans

 

[Superdemon]

I would stay away from Ultra until they can explain what happened with the last PSU [H] tested.

 

[Dangman]

Check out the jonnyGURU review of it:
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=23

According to that review, you need to add a few more" hard drives, PCI cards and/or some USB devices" in order to make it run better. And why spend all that money on drives, PCI cards and USB devices when you could've just bought a new power supply and be done with it?

But to answer your question, yes the PSU would be enough for 8800GT SLI as long as you add a few more hard drives, etc. And it is SLI certified and does have 35A on the +12V rail.

However I do recommend getting a new power supply. You're spending quite a bit of money on video cards. Kind of dumb to trust that kind of money with that kind of PSU.