Power, heat and noise
All this talk of architecture and designing a GPU to achieve the highest performance-per-watt metric is reinforced with our power-draw test. The quoted figures represent the consumption evaluated by a mains-connected watt meter that's plugged into the Corsair 600T's PSU: system power, if you will.
Perhaps it's not wholly surprising that GTX 680 sneaks in under Radeon HD 7970. Its idle power-draw is also now comparable to AMD's. Higher performance and (very slightly) lower power-draw is sure to make for a nice bang4watt metric.
And it's not overly toasty.
Consuming 50W less than a GeForce GTX 580 and a revised cooler combine to make the GTX 680 the quietest card in our line-up. It produces a slight hum when gaming, and it's a sound that we can certainly live with on a day-to-day basis.