I have a Corsair CS Series, CS550M psu and a XFX Radeon RX 580 GTS gpu. I am having trouble finding the correct cable to power the card from the psu. I have two available 6 female pin ports on the psu and the card has an 8 pin female port. The card came with a 8 pin male to dual 6 pin female cable which is incompatible with my psu. Of course I don't have the original cables that came with the PSU. Can someone please lend me some guidance as to what cable I need and where I can get it? I tried a 8 pin to 8 pin cable (4+4) but it didn't plug in easily and didn't power the card.