well if ur running 2 8800s in SLI you oughta get a PSU with much more stable rails .. And IMO the Powersafe/Vip ones aint that stable and are just single rail ones...
Spend a bit more and go for a Coolermaster Extreme Power 500 or 600W if ur on a budget, it'll do u good..
Look here for a tiered rating of the various PSUs and see where Zebronics stands...
http://www.xtremesystems.org/forums/...d.php?t=108088