The GTX 680 draws fairly little power given its performance. Under load, the whole system pulled 349 watts, 6% less than the HD 7970 and 14% less than the GTX 580. The overclocked GTX 680 Phantom only consumed roughly 2% more power than a standard version.
The Phantom’s operating temperatures were remarkable, never exceeding 75 degrees under full load, making it five degrees cooler than the HD 7970 as well as a standard GTX 680.