"Micro Cooling Fan" exhaust volume can say is a more comprehensive indicator, so we can say that the amount of exhaust is the most direct factor to measure the performance of a fan. If a fan can be up to 5000 rev / min, but the fan if it is flat, then it will not form any airflow, so the relationship "Micro Cooling Fan" in the amount of exhaust, the blade angle is the decisive factor. Test a fan exhaust volume method is very easy, just put your hand near the heat sink feel the wind blowing intensity can be, generally good quality "Micro Cooling Fan", even though we are far away from it location, but also still can feel romantic, it is the cooling effect of a good performance.