Sound Level And Temperature: Stock Settings
We begin by measuring the operating temperatures of our seven GeForce GTX 670s at their factory clock settings. On the next page, we also report thermal conditions at an overclocked setting to give enthusiasts an idea of how these cards' coolers perform.
At idle, Zotac and Gigabyte achieve the lowest temperatures. Under full load and in the gaming benchmark, Zotac assumes the lead, a feat that is unfortunately accompanied by a significant sound level.
Speaking of acoustics, the Galaxy/KFA² card idles a little warmer than the other contenders at 38°C, but is able to run its fan very slowly as a result, generating no perceivable noise. Under load, its temperature is just a little higher than Nvidia's reference card. Its noise level appears to be similar to Asus' board, though it suffers from an extremely annoying high-frequency coil chirp. We contacted Galaxy/KFA² about this issue, which may be just a problem isolated to our test sample. A GeForce GTX 680 from the same manufacturer was louder overall, but lacked the chirping issue.
Also under full load, Gigabyte's card winds up louder than Asus and Galaxy/KFA², but still falls below the 40 dB(A) mark.
One more thing we'd like to mention is cooling on the DC-DC converters. It seems that nearly all add-in board vendors focus their cooling efforts on the GPU and somewhat neglect the power circuitry. Granted, the DC-DC converters of heavily-overclocked cards rarely exceed 100°C. But even temperatures around 95°C don't inspire a ton of confidence about a card's longevity. Enthusiasts willing to increase their card's core voltage will also want to keep this in mind.
The Zotac and Gigabyte cards exhibited the lowest temperatures on their voltage regulation circuitry, which may or may not affect your buying decision. In general, the models based on Nvidia's longer GeForce GTX 680-style PCB fare the best, possibly because they have more room for an optimized layout, or maybe because they employ the 680's DC-DC converter components.