4870x2 quad crossfire power question

[heavy_metal]

I might have the opportunity to get a 4870x2 for a trade of my GTX275 to go with my other 4870x2 which I think would be sweet for quad-fire, but I needed to know if my PSU could power my system or not. I have a Corsair TX850 power supply which I use to power my system as of now. And if it isn't enough power what would you recommend for a power supply please be specific in Wattage and Brand. Any Help is appreciated. Thanks for the Help. Also should I have posted this here or in power supply area?

Current Specs are:
3.6Ghz Core i7 920
6gb of Ram
30gb SSD
2 1TB Western Digital
1 1.5TB Western Digital
1 500Gb Western Digital
4870x2 2GB Video Card
GTX 275 for extra Screens as of now
Cooler Master Storm Scout
P6T Deluxe V1
Corsair H50 Water Cooler
Corsair TX850 as of now.

 

[rolli59]

This is what Sapphire says 1kw http://www.sapphiretech.com/presentation/product/?psn=000101&pid=180 It is the same as XFX says. Then again the Corsair is known to be underrated.

 

[heavy_metal]

Best answer selected by heavy_metal.