Fan Noise
In past years, gamers would accept everything for a little bit more performance. Nowadays, users are more aware of the fan noise and the power consumption of their graphics cards.
We use the Bruel & Kjaer 2236 sound-level meter (~$4,000) to properly test the fan noise a card emits. It has the measurement range and accuracy we are looking for.
The tested graphics card was installed in a system that was completely cooled system passively. That is, passive PSU, passive CPU cooler, and passive cooling on the motherboard and on a solid state drive. Noise results of other cards on this page are measurements of the respective reference design.
This setup allows us to eliminate secondary noise sources and test only the video card. To be more compliant with standards like DIN 45635 (we are not claiming to be fully DIN 45635 certified), the measurement was conducted at a distance of 100 cm and 160 cm off the floor. Ambient background noise in the room was well below 20 dBA for all measurements. Please note that the dBA scale is not linear but logarithmic. 40 dBA is not twice as loud as 20 dBA, as a 3 dBA increase results in double the sound pressure. The human hearing perception is a bit different, and it is generally accepted that a 10 dBA increase doubles the perceived sound level. 3D load noise levels were tested with a stressful game, not with Furmark.
Idle fan noise is very low, making the card almost inaudible in idle. The card remains quiet under load, but I think it could be quieter, given its load temperature is 62°C. Other GTX 660 cards we reviewed earlier were significantly quieter than the GTX 660 GAMING. One such cards is the MSI GTX 660 Twin Frozr OC: It is quieter (23 / 28 dBA), has a higher overclock, and currently sells for less.