I have a 2GB GAINWARD GTX770 PHANTOM GPU and a 600W Seasonic PSU (SS-600HM Active PFC F3 (Ball bearing)), I also have an 8pin to PCI-E 8pin(6+2) connector. there doesn't seem to be any valid connections although the 6 pin does seem to fit into the gpu but the problem is the psu's male 8 pin to doesn't connect to the cable's female 8 pin, is it the wrong cable do i need another cable as well or do i need a different PSU?