Fan NoiseIn the past years users would accept everything just to get more performance. Nowadays this has changed with people being more aware of the fan noise and power consumption of their graphic cards.
In order to properly test the fan noise a card emits we are using a Bruel & Kjaer 2236 sound level meter (~$4,000) which has the measurement range and accuracy we are looking for.
The tested graphics card is installed in a system that is completely passively cooled. That is passive PSU, passive CPU cooler, passive cooling on the motherboard and Solid-State HDD.
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 100 cm distance and 160 cm over the floor. The ambient background noise level in the room is well below 20 dbA for all measurements. Please note that the dbA scale is not linear, it is logarithmic. 40 dbA is not twice as loud as 20 dbA. A 3 dbA increase results in double the sound pressure. The human hearing is a bit different and it is generally accepted that a 10 dbA increase doubles the perceived sound level.
On the previous page you read about the power consumption of the GeForce GTX 480. This should give you an expectation what you will see here. Basically all the power consumed by the card ends up as heat and that has to go somewhere.
In idle the fan noise is decent, but certainly not anywhere what we have seen on HD 5870s with custom cooling solutions from AIBs like PowerColor or ASUS. Under load the fan ramps up quickly to make you wish you had earplugs. Same picture here again: similar noise to NVIDIA's last generation cards, while AMD has worked on their noise levels and delivered substantial improvements.
NVIDIA's fan control profile is also set in a way that quickly ramps the fan up and down as load changes, resulting in a more audible experience since your brain tends to notice changing noise levels much more than a constant level.