So i just bought an XFX 750W Black Edition because after some research i found out it would be sufficient for GTX 570 SLI, but now after i've purchased it i've heard from several people that it won't be enough. I also want to overclock eventually so i really need some extra power.
Should i return it and buy the 850W version or will it be fine.
You need to add up all the wattages required by all of the components that make up your system (motherboard, videocard, peripheral cards, case fans, etc.) and multiply that figure by at least 1.5 X of the total to see how much you'll actually need (TOTAL WATTAGE). Remember that it's always good to have extra than to need it and not have it! If the final TOTAL is under the 750W value then it should suffice but if not, then go ahead and return it for the 850W version. Good luck!