Recently we have changed our method of measuring noise levels. 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 with our Extech digital sound level meter to mirror a real world situation.
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
When we turned on the MSI Wind Top AE2400 initially the fans kicked in at 100% and we couldn't believe the noise generated. Thankfully after 10 or so seconds it dropped to more respective levels.
It is only slightly audible under general use, as the rear fan expels warm air from the top and rear of the chassis. When fully loaded however it generates a considerable level of noise which might become obstrusive in a bedroom environment. To be fair, it never reaches this level when watching a BluRay or HD video content, only when gaming.