Noise levels
Noise levels were measured using an Extech 407727 Digital Sound Level meter placed along the edge of the motherboard, 1" from the graphics card and out of the direct path of airflow. We recorded noise levels after 10 minutes idling at the Windows desktop, and again after 10 minutes rendering this stunning scene from Oblivion at 1280x1024 with all the in-game eye candy cranked. Cards were tested at both their default and overclocked speeds.
Our sound level meter doesn't have the sensitivity to pick up noise levels below 40 decibels, and the OC2 is quieter than that at idle, even when overclocked. That's an impressive result for an active single-slot cooler, and a feat only matched by the passively-cooled Gigabyte 8600 GTS.
Under load, the OC2's fan starts to spin loudly enough for our sound level meter to get a reading. The BFG card is still the quietest of the lot when running at stock speeds—by more than a decibel and a half. It's not the quietest when overclocked, but it only trails the Asus card, which is running at lower clock speeds, by a smidgen.
Power consumption
System power consumption was tested, sans monitor and speakers, at the wall outlet using a Watts Up power meter. We used the same idle and load conditions as our noise level tests.
With higher clock speeds than the rest of the pack, it's no surprise to see the OC2 pulling more watts at idle. Only the Gigabyte card's conspicuously high power draw keeps the OC2 from drawing the most power under load, as well.
GPU temperature
We tracked GPU temperatures using Nvidia's nTune system utility, which can log temperatures to a text file. Again, we used the same idle and load conditions as our noise level tests.
BFG makes much of the ThermoIntelligence heatsink's superior cooling performance, but it's hard to see what they're on about based solely on these results. Note, however, that the BFG card is running at higher clock speeds than the others and drawing more power in the process. The OC2 is also competing with louder dual-slot coolers on the Asus and MSI cards.
