Power consumption
We measured total system power consumption at the wall socket using an Extech power analyzer model 380803. The monitor was plugged into a separate outlet, so its power draw was not part of our measurement.

The idle measurements were taken at the Windows desktop. The cards were tested under load running Oblivion at 1280x1024 resolution with 16X anisotropic filtering. We loaded up the game and ran it in the same area where we did our performance testing.

The G84 is an efficient architecture in more ways than one. It performs well, and it does so without drawing too much power.

Noise levels and cooling
We measured noise levels on our test systems, sitting on an open test bench, using an Extech model 407727 digital sound level meter. The meter was mounted on a tripod approximately 14" from the test system at a height even with the top of the video card. We used the OSHA-standard weighting and speed for these measurements.

You can think of these noise level measurements much like our system power consumption tests, because the entire systems' noise levels were measured, including the Zalman CNPS9500 LED we used to cool the CPU. Of course, noise levels will vary greatly in the real world along with the acoustic properties of the PC enclosure used, whether the enclosure provides adequate cooling to avoid a card's highest fan speeds, placement of the enclosure in the room, and a whole range of other variables. These results should give a reasonably good picture of comparative fan noise, though.

Notice that the GeForce 7 cards don't look so good here, especially at idle. That's because their coolers appeared to be running at full-tilt no matter whether the systems was running a game or sitting idle at the Windows desktop. I even tried disabling Vista's Aero look, but it didn't seem to help. Looks to me like we found another bug in Nvidia's Vista x64 drivers.

At any rate, the 8600 cards come out looking pretty good, with GTS tying the Radeon X1950 Pro. None of these cards are as quiet as the high-end cards with massive dual-slot coolers, though.