"24V DC Cooling Fan" main role is to heat, and radiators are required by forced convection fan to accelerate heat loss, so a fan is good or bad, on the whole cooling effect plays a decisive role. With an excellent performance of the CPU fan is one of the key factors to ensure the smooth functioning of the entire computer. Fan speed is the number of revolutions per minute of the fan blades, the unit is rpm. Fan speed, "24V DC Cooling Fan" number of blades, tilt, height, diameter and bearing system is determined by the motor inside the coil turns, the operating voltage. Fan speed and quality are not necessarily linked. Fan speed can be performed by measuring the internal speed signal can also be measured by an external (external measure is to see how fast the turn of the "24V DC Cooling Fan" with other instruments, internal measurements directly to the BIOS can see, you can also look through the software. internal measurement error is relatively larger).