you must have an old hx520. i have 4 models, 2 came with only 6 pin connectors, and the newest 2 came with 8pin. if you contact corsair, they'll most likely send you the cables you need directly for a shipping fee. i requested replacements for my older ones and shipping was $8, IIRC.
I GOT SCREWED! I already ordered. I can't see the actual holes and I wasn't quite sure if it's the right one. Because I have a 6pin pcie -> 6+2 pin and it wouldn't fit.