So I build My Computer about 2 months ago and i was starting to look into SLI with two gtx550ti's(i bought my 550 for 100 and theyre dropping prices fast so i thought id just buy another because the price of 560s are about the same ill pay for both 550s). I was kinda worried about not having enough watts to power the whole computer.
AMD FX 4100 OC 4.15mhz 8GB 1866 DDR3 2TB 7200RPM HDD 3 120mm Fans HDD Dock on the Top of the Case
And the final item, TX650M Corsair Power Supply
Your psu should be OK. But verify that your motherboard supports sli.