I agree with Jaslion. First, do you see that 520W under the 12V rails? Modern systems draw nearly all their power from the 12V rail, so you really have something closer to a 550W PSU, not 700W. Second, what is the cable count like? Do you even have 6 or 8pin plugs? I'm only guessing here, but I'll bet you don't have the plugs needed for a GPU. I can't find a review for the PSU so I could be wrong, but I agree that it's probably junk and should be replaced.