No, do not use 1 6 pin when it requires 2. Just use 2 6pins and reduce the fan speed in AMD Catalyst. Lack of power can potentially cause games and your computer to crash. It can also harm the card itself.
ok, well its my first build and its pretty noisy as in rushing air noises which is a good thing but just not needed when im not gaming or not using graphics intensive programs. its on 20% minimum.