Akasa AK-CB052 cable adapter PCIe 6-pin to 8-pin PCIe 2.0 (Electronics)
This is exactly what I was looking, having a power supply with two 6-pin connectors and bought a GTX 980, I was so pissed off ... The latter requires 2 8-pin connectors. So I ordered 2 adapters 6> 8 pin. They are very good bills and perfectly fulfill