Fan Noise
In past years, gamers would accept everything for a little bit more performance. Nowadays, users are more aware of their graphics card's fan noise and power consumption.
In order to properly test the fan noise a card emits, we use a Bruel & Kjaer 2236 sound-level meter (~$4,000). It has the measurement range and the accuracy we are looking for.
The tested graphics card is installed in a system that does not emit any noise on its own, using a passive PSU, passive CPU cooler, passive cooling on the motherboard, and 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 is conducted at a distance of 100 cm and 160 cm off the floor. Ambient background noise inside 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 are tested with a stressful game, not with Furmark.
ASUS engineered their STRIX series with a unique feature. With the card in idle or a light load, the fans will stop completely, providing a perfect, noiseless experience. Once temperatures exceed 67°C, the fans will spin up, but do so very quietly.
Even while gaming at full tilt, with a full load, the ASUS STRIX GTX 970 is extremely quiet, barely audible, no matter what you throw at it. Good job, ASUS!