We measure the amount of power drawn from the wall by the entire test system. Our Core i7-5960X CPU is heavily overclocked and has a large bearing on the power draw readings when it is heavily loaded in GTA V. The important information is the difference in power draw levels between each card.
Gigabyte's heavily-overclocked GTX 950 uses more power than competing vendors' offerings while gaming. This is unsurprising given the card's 1481MHz core clock while gaming and its higher performance than other GTX 950 solutions that we have tested.