The PWM regulates the fan’s RPM the fan changes the RPM depending on the temperature requirements, thus eliminating unnecessary noise. This slow rotation isn’t ideal for modern computers. However, they can control low voltage so that they rotate slowly. You can control rotation speed for 3-pin fans but to a certain extent. For instance, when the processor is carrying out heavy work, the PWM fans increase the voltage for temperature control and vice versa. The 4-pin or the PWM fans can control the fan’s voltage. There are four major differences between them: Pulse Width Modulation (PWM) Keep scrolling to discover the key differences between the 3-pin and 4-pin fans. What are the differences between the 3-pin and 4-pin fan?ĭespite both being fan types, the two fans’ service delivery is different. Therefore, the longer the voltage applied to the fan motor coils, the faster the rotation. It regulates the Revolutions Per Minute (RPM) and PWM signal while consequently providing the speed sensor’s feedback. This 4th wire is essential as it properly cools the CPU in modern PCs. This PWM’s main function is controlling the load’s power supply and the fan impeller’s rotating speed. The 4-pin fan is present in modern motherboards, and the key difference from the 3-pin is the 4th wire, the Pulse Width Modulation (PWM). After this, the fan speed is controlled by increasing or decreasing the voltage across the power cable. The speed sensor controls the motor’s power level by supplying the fan’s rotation speed at a normal voltage of 5-12 volts. The 3rd wire shows the tachometric signal, or the speed sensor, that checks the fan’s performance and speed. The first wire represents the power (4 to 12 volts) 2nd is the ground wire. This fan type has three indicators as per the number of wires. Keep reading to learn and understand the format and the difference between the 3-pin fan and the 4-pin. The 3-pin fans have potential if controlled using the format indicated in the article.

3 pin fan controller