They did, but mainly to supply power for the POST process and to determine what power requirements the GPU had. There's a lot of activity for things like power bring-up and waking up the card from idle that needs power from the PCI-E/PCI/AGP slots first before acknowledging additional power being fed by an auxiliary power connector.
In fact, this is one of the reasons why some GPUs will power on and function without the power connector plugged in, as some GTX 750 Ti cards recently proved. The GPU itself uses very little power at POST and in idle mode that it doesn't need auxiliary power, but it's a help when you need to extract more speed from the chip.
Well I dont get it.
Why would AMD make single six pin if their card is just to power hungry?! PCB looks better on RX 480 (maybe not efficient) than on GTX 1080FE.
What about GTX 750TI OC using more than 80W from PCIe?
Edited by CataclysmZA - 6/30/16 at 8:51am