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.

I would characterize the fan noise of the HD 4770 is sufficiently quiet. Based on the temperatures we are seeing there is still plenty of headroom left to quieten down the cooler in both idle and load. I am sure AIBs will also look at alternative coolers to use on this card to either improve performance, acoustics or reduce the price.

Initially our sample showed a strange fan behavior. The card would randomly ramp up the fan even though temperatures suggested this should not happen. After checking in with AMD they sent us an updated BIOS. The version number of the old BIOS ends with 032516, the new one with 32832.