I'm building a computer for a friend and I have most of it set up but the power supply seems to not have the right connector. I put up a video here(first one in the video clips section) that shows the two connectors that will fit in it but I don't think that either of them will work because the connection has 8-pins on it. Also one of them says PCI-E on it. The power supply is 680 watts. Did I not get one powerful enough?