These power results are a bit odd since we're driving three monitors throughout our tests. That causes the Radeons to draw quite a bit more power at idle than we'd usually expect, and AMD's ZeroCore power feature doesn't seem to work, either, robbing the Radeon 7000-series cards of their usual advantage when the display is in power-save mode.
The GTX 670 doesn't appear to be affected by similar problems, and its power draw at idle is nice and low. Remember, that's 68W at idle for a whole system built on Intel's beefy X79 platform. When running a game—Skyrim, in this case—our test system draws a little more power with a GTX 670 installed than it does with a 7950 installed. That's a surprise given the two cards' specs. We're curious to try this again with a different game or two in the future.
Noise levels and GPU temperatures
You know how I said the GeForce GTX 690's smooth fan action feels like money? Yeah, well the GTX 670's cooler sounds cheap. That's why the 670 is relatively noisy at idle, even though it has very little power—and thus heat—to dissipate. The GTX 670's blower emits a rough, friction-filled whine. It's not especially loud, and heck, the thing manages not to register too high on decibel meter under load. Tucked inside of a case that insulates sound well, you might barely notice it. Still, this thing isn't Nvidia's best work. I'd be looking toward a card with an aftermarket cooler, most likely.