"Micro Cooling Fan" noise and friction, air flow related. Fan speed, the greater the amount of wind noise caused will be greater, additional fan vibration itself also can not be ignored. Of course, the fan itself high quality shock will be small, but the first two were, but it is difficult to overcome. To solve this problem, we can try to use a larger size "Micro Cooling Fan". Should be under the same amount of wind, the large fan noise at low speed work should be less than the work of a small fan noise at high speed. Another factor is that we tend to ignore the fan bearings. Since the "Micro Cooling Fan" to friction between the shaft and the bearing is rotated at a high speed collision, it is also a major source of fan noise.