Fan Noise

In 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.

Despite the powerful Arctic Cooling heatsink, the fan is running fairly fast which results in noise levels slightly above the HD 4770 reference design. Considering idle temperatures of 37°C and 55°C under load it would have been extremely easy to just slow down the fan resulting in much less fan noise.

To give you a sense of perspective what would have been possible, I set the fan speed to 5% fixed. Normally the card reaches about 55% fan speed under load @ 57°C @ 33.5 dbA. With the fan set to 5% fixed the card hit 77°C under load @ 22.0 dbA. 22.0 dbA is so quiet that any other noise source in your room will overpower it.