It will run it with no problem. I am powering a GTX560Ti 448 core with an OCZ Fatality 550 watt psu. You can easily run anything up to a GTX570 with that unit you have. My card, which is basically a gimped 570, says it requires 38 amps, so a 560 is probably around 32a
Yeah, but what about that 18A per 12V rail? I'm a little confused about how to interpret those 4 x 12V rails at 18A each.