I have the EVGA GTX 560 Ti 448 Classified Ultra video card and want to get a second for SLI but when I use the eXtreme power supply calculator is says I will need 950w of power. With my pc only having a 850w psu I would need to upgrade. I have seen reviews and benchmarks of PC's using two GTX 580 3GB cards being used on 750w.
How much power would I really need to run two of my 560's?
I do not want to have to upgrade my PSU as I just got a new one a couple months ago.
Asus Crosshair V Formula Motherboard
AMD FX-4170 4.2Ghz Quad Core
16GB Kingston HyperX 2x8GB 1600Mhz Ram
Thermaltake Touphpower Grand 850w PSU
NZXT Switch 810 Full Tower Case with 9x Cougar Vortex 140mm Fans and Two 120mm Cougar Vortex fans
Antec H20 620 Liquid Cooler
Two 500GB Seagate Barracuda HDD's
One GTX 560 Ti 448 Ultra