I just got an asus gtx 770, it has two power connector sockets, an 8 pin and a 6 pin, ive also got a cable that came with my power supply which at one end is an 8 pin to go into my psu and the other end has a 6/8pin which then has a short cable off it to another 6/8pin both labeled pci-e, is sticking both ends labeled pci-e into my gpu and the other into my psu the right thing to do?