Recently we have changed our method of measuring noise levels. We have built a system inside a Lian Li chassis with no case fans and have used a fanless cooler on our CPU. We are using a heatpipe based passive power supply and an Intel SSD to keep noise levels to a minimum. The motherboard is also passively cooled. This gives us a build with completely passive cooling and it means we can measure noise of just the graphics card inside the system when we run looped 3dMark tests. Ambient noise in the room is around 20-25dBa. We measure from a distance of around 1 meter from the chassis and 4 foot from the ground to mirror a real world situation.
Why do this? Well this means we can eliminate secondary noise pollution in the test room and concentrate on only the video card. It also brings us slightly closer to industry standards, such as DIN 45635.
We load the card with FurMark.
KitGuru noise guide
10dBA – Normal Breathing/Rustling Leaves
20-25dBA – Whisper
30dBA – High Quality Computer fan
40dBA – A Bubbling Brook, or a Refridgerator
50dBA – Normal Conversation
60dBA – Laughter
70dBA – Vacuum Cleaner or Hairdryer
80dBA – City Traffic or a Garbage Disposal
90dBA – Motorcycle or Lawnmower
100dBA – MP3 player at maximum output
110dBA – Orchestra
120dBA – Front row rock concert/Jet Engine
130dBA – Threshold of Pain
140dBA – Military Jet takeoff/Gunshot (close range)
160dBA – Instant Perforation of eardrum
The cooler is reasonably good, although both can be heard when fully stressed in Furmark. Adding another raises the noise a little in both configurations.
In three way CFx, the noise levels are extremely high, due to the close proximity and raised ambient temperatures (to over 100c). We recorded around 60 dBa when all three cards were running 3dMark 11.
Here is a video of the noise levels of the system at full load with 3 cards in CrossfireX. Its not even remotely scientific, but turn the volume up to get an idea !