PWM fans, unlike 3-pin or 4-pin fans, can be regulated via the motherboard. This allows the fan to operate at multiple speeds and automatically adjust its speed based on the temperature. A PWM fan is even more practical if a temperature sensor and a fan controller are present in the PC system. While not strictly necessary, these features give the user even more options to control the temperature in their case.
With a PWM fan, in addition to this factor, you should also consider the speed, airflow, and noise level, as with other fans. Those who want to keep their case quiet should look at the wide range of silent fans with PWM signals, which use special techniques like specialized bearings or adjusted rotor blades to keep the noise level low.
In an office computer or HTPC, a PWM fan is rarely necessary. Therefore, you should ask yourself beforehand whether a PWM fan is necessary for the intended purpose. PWM fans can be mounted not only in the case but also on radiators and CPU coolers. This allows you to regulate the temperature and speed of radiators and CPU coolers as well.
PWM fans are offered in various designs and can also be illuminated with LEDs. This, of course, only makes sense if the fan can be seen from outside the case through a window or similar. Additionally, the rotor blades can take different shapes to either increase airflow or reduce noise.
