When playing Crysis 2, the GTX 670 consumed slightly less power than the GTX 680 and only a tad more than the HD 7950, while its idle performance was about equal to both cards.
As you’d expect, the GTX 670 doesn’t run very hot, especially with the Gainward Phantom cooler. Temperatures never exceeded 71 degrees, which isn’t as cool as Gigabyte’s HD 7950, but it’s still remarkable for a high-end graphics card.