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.

When you see a card design that replaces the reference single slot cooler with a bigger dual slot cooler that also offers more bling effects you would expect that the fan noise drops. However, in our testing the VVIKOO GeForce 9600 GT Turbo tends to be quite a bit louder in idle than comparable 9600 GTs with the reference cooler. Under load this changes and the card is quieter thanks to the better cooling potential of the cooler.
What I still find interesting is that the 8800 GT, which is a higher performance product, can operate significantly quieter than the 9600 GT. For manufacturers its always a tradeoff between fan noise and card temperature. It is my impression that (too?) many people just ask "what's the temperatures like?" and almost nobody asks for more than "is it noisy?". Temperatures are easy to measure with a zero $ investment, fan noise is not. Also "noisy" is an extremely subjective criteria which is not easy to quantify with anything other than absolute numbers. This gives me the impression that manufacturers tend to overoptimize temperatures and accept a bit more fan noise.