Question about SLI and power consumption

[Locknuts]

You can get away with a HX650 (I'm assuming that's the one you have?) with 2 x 560tis but 2x 570s is really pushing it. I'd just sell it and get a GTX 970. You could SLI 2 of those with your PSU. I wouldn't crossfire any high end AMD gpus with that PSU though. They're a bit thirsty.