So, I'm guessing its a 6 series card... Its a power cable, ebay, xoxide.com, newegg.com, zipzoomfly.com, monarchcomputer.com.
Search for molex converter or pci express power cable.
Dirt cheap
ok 1st of all that cable broke. When my stupid uncle was tryin to assemble it. Maybe this will help. The psu is a Antec truecontrol
and the video card is a sappfire radeon x850 pro.