I've got a 2009 Mac Pro. I'm considering getting an AMD Radeon R9 Nano graphics when it comes out later this month, and I'm trying to figure out how I can power it. The card requires 175W, and a single 8-pin (150W) power connector. Problem is, each of the two PCIe auxiliary power outlets on the motherboard is 6-pin (75W). I realize that plenty of people use 6-pin to 8-pin adapters, but I'd rather not if possible. I'm wondering if there exists a dual 6-pin to single 8-pin Y-cable which would suit this purpose. I haven't been able to find one, does anyone know if they exist?