The amount of noise generated by the coolers was measured with a digital noise-level meter Center-321 (0.1dB accuracy) using A-curve weighing. The measurements were done at night in a totally quiet apartment – the level of ambient noise was as low as 31.6dBA. The amount of noise was measured:
- At a distance of 3 centimeters from the CPU cooler when the latter was the only operating component of the system. This is the bare noise of the cooler, without any interference from other system components.
- At a distance of 1 meter from a closed and fully functional system case (with the side-panel fan turned off) in the point where the PC user is supposed to sit. This is the amount of noise you’ll hear while working at the computer (the system case is placed into a niche of a computer desk, the photo is available here)
- At a distance of about 3 meters from the system case. This reflects the amount of noise you’ll have if your PC is working on a 24/7 basis and you are having your rest in the same room.
The noise level of the system case can be viewed in this diagram. The subjectively comfortable level of 36-37dBA is marked with a dashed line in the diagram. The coolers are sorted in the diagram in the order of increasing loudness. Here are the results:
So, the Scythe Andy Samurai Master, the weakest cooler of this review in terms of performance, proves to be the quietest of all. The leader is closely followed by the Scythe Infinity and the Thermalright Ultra-120 eXtreme that have one 1200rpm fan. Next go the Thermaltake Big Typhoon and Zalman CNPS9700 LED together with the pair of tower-like coolers with two 120mm fans. The fan of the Enzotech Ultra-X is the loudest of all but the noise is compensated by this cooler’s highest performance. It should be acknowledged that the noise of the Enzotech Ultra-X is quite comparable to the other coolers at a distance of 3 meters from the system case.
A curious fact, the Scythe Andy Samurai Master and the Thermaltake Big Typhoon were tested with the same fan from the Enzotech Ultra-X at the max fan speed (2530rpm), yet the Big Typhoon proved to produce more noise. This must be due to the difference in the heatsink design because it is the noise from the flow of air that is measured at such a high speed rather than anything else. The Enzotech Ultra-X has the narrowest heatsink with minimum resistance. The Scythe Andy Samurai Master, on the contrary, has a heatsink with dense plates and also has an auxiliary heatsink placed right above the heat pipes. I guess this explains the difference in the noise level.