Manufacturers

Kama PWM 120mm Cooling Fan

Kama PWM 120mm Cooling Fan [97 in stock]

£8.50 (£9.99 inc VAT)

PWM (Pulse Width Modulation) is a method of slowing down the speed of a fan by switching it on and off very quickly, in contrast with the simpler method of reducing the supply voltage. The advantage of PWM is that the speed of the fan is more controllable, and power is not lost (or heat produced) through the component reducing the voltage, usually a resistor. In addition, PWM fans do not stall or fail to start at low speeds.

Scythe 120mm Kama PWM Cooling Fan

Whether you use PWM fans in your PC will be determined by your motherboard, and whether it has 3-pin or 4-pin fan headers. PC PWM fans have small 4-pin connectors instead of the more common 3-pin connectors found on non-PWM PC fans. The fourth pin is used for the PWM signal, and is used by the motherboard to control the speed of the fan. Most motherboards allow you to configure fan speeds either in the BIOS or through Windows using a supplied program. They can also allow you to set the speed of the fan so that it increases in line with temperature, thus reducing unnecessary noise.

It is perfectly acceptable to connect a 3-pin fan to a 4-pin motherboard fan header (leaving the fourth pin unused), in which case the fan will operate normally. However, you will not be able to make use of any functionality that the motherboard offers in terms of PWM fan speed control. In this case, if you don’t want your fan to run at full speed all the time, you may wish to use a fan controller.

If you decide to make use of your motherboard’s ability to control the speed of a 4-pin PWM fan, then Scythe’s PWM fans are naturally of the very best quality and offer excellent airflow and low-noise characteristics.

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See also:

Ultra-Quiet 120mm fans