I had to get a 6 pin to 8 pin PCI express plug adapter for my card. They were hard to find, and everyone locally told me it was a bad idea cause if you didn't have an 8pin already on your power supply it was likely not big enough. I kind of laughed at the idea cause I had a 750w, and the 12V was rated for well over the requirement of the video card. The thing I don't quite understand is looking at the pinout of the 8 vs 6, the extra two pins are just another 12V power, same as the existing. All the adapter is is a jumper going from one set to the other. Seems like they could easily do that on the circuit board and keep the 6 pin standard rather than opening another 8 pin standard.
I bought one 8 pin adapter, and it was wrong. Even though the description called it a 6 pin pci express to 8 pin pci express, it came with an 8pin connector for motherboard power and it wouldn't fit. I had to wait 3 more days for the correct one :(
Can't sleep, clown will eat me.