Originally Posted by Xristo
A quality 750w psu is good for any non sli system .
I had problems with my 650w , in benchmarks my pc would just switch off .. due to lack of power since i have everything overclocked .
While I agree that cheap/bad PSU's aren't always what they're rated, you are entirely wrong regarding to your usage of wattage.
Your 650W made your system switch off because the PSU sucked... Not because of wattage.
It's not just the wattage of a PSU but amps and decency of a PSU. 1Kw is WAY overkill for your current system. Your system never draws beyond 500W unless you have extreme OC with top end watercooling - then it may be 540W at most...
Not to mention a decent PSU will in many/most cases supply even more than peak rated wattage to your system. Some 500W PSU's only fail when they are to deliver 650W. I don't make these things up, this is knowledge based on PSU reviews and experience from consumers.
I belive Google would be suited for you. No offense, but you need it.