We'd like to cover a few final data points before bringing this article to a close. Throughout all of our benchmarking and testing, we monitored how much power our test systems were consuming using a power meter. Our goal was to give you an idea as to how much power each configuration used while idling and under a heavy workload. Please keep in mind that we were testing total system power consumption at the outlet here, not just the power being drawn by the motherboards alone.
Our power consumption testing revealed some interesting results. While idling, the new GeForce GTX 285 consumed the least amount of power...by far...besting the other cards by about 30 - 40 watts. Under load, however, power consumption jumped considerably and the GTX 285 nearly matched the GeForce GTX 280. The GTX 285's peak power consumption was also well north of the 1GB Radeon HD 4870's.
Despite the surprisingly high peak power consumption numbers--we expected larger saving due to the die shrink--the GeForce GTX 285 ran relatively cool and its fan never had to spin up to more aggressively manage the heat. In fact, after hours of testing, the card was only warm to the touch when we pulled it out of the test rig.