3 Pin vs 4 Pin Fans Connector for CPU, Which One To Have on Header?, What’s a Difference?

If you have already assembled a computer or building a PC on your own. You may have noticed that often many brands of PC fans have 3 pins or 4 pin CPU connectors. Because there are some differences between 3 pin and 4 pin fans. I will let you know this as well as which is best in comparison 3 Pin vs 4 Pin Fan Connectors.

Due to the increase in speed and power consumption of processors, with other components of computers would produce a huge amount of heat as a side effect of normal operation.

For such, fans being used to control the temperature to ensure reliability, energy efficiency, and speed feedback. And to prevent instability, and damage that will shorten the life of the PC, fan controls rotation speed and voltage supply.

Let’s get to know which one is the finest for your build and upcoming generation between 3 Pin vs 4 Pin Fans.

3 Pin vs 4 Pin Fan

3 Pin Fan

The 3 pin fan connector has three indicators (as per the number of wires): The first wire is for power (4 to 12 volts), 2nd is for ground and 3rd wire is for a tachnometric signal (speed sensor) this sensor monitors the fan speed and performance.

A tachnometric signal adjusts the level of power applied to the motor by transmitting the speed of rotation of the fan impeller at a nominal voltage between 5 to 12 volts. In this way, the fan speed is typically controlled by increasing or decreasing the voltage across the power cable.

4 Pin Fan

4 pin fan headers are commonly found in modern motherboards. The 4 pin fan connector is slightly different from the 3 pin connector also works the same but the additional 4th wire is PWM (Pulse Width Modulation) used for controlling the power supply of the load and rotation speed of the fan impeller.

The PWM wire is very important for proper CPU cooling in modern PC towers. It adjusts the RPM using a PWM signal and simultaneously provides tachometer feedback. In other words, the longer the voltage is applied to the fan motor coils, the higher the rotational speed and vice versa.

I hope you got clear of 3 and 4 pin fan connectors. Now let’s see the difference between 3 pin and 4 pin fans.

Difference Between 3 Pin and 4 Pin Fan

There are four differences between 3-Pin and 4-Pin Fan connectors. Let’s get to know:

1. PWM (Pulse Width Modulation)

PWM fans i.e 4 pin fans simultaneously control the voltage of the fan. For example, if the processor is busy with heavy work on the computer the 4 pin fan increases the voltage in order to control the temperature. Similarly, as the processor shifts to light work, the voltage and RPM of the fan slow down automatically.

You can also control the rotation speed in the case of 3 pin fan connectors but the thing is that they are up to some extent and not as automatic and accurate as much as 4 pin fans. Although they can control their voltage. That is, the less voltage we apply the slower will rotate. This might not be suitable for modern PC needs.

That’s why PWM presents on the modern motherboard, and other video cards, etc.

2. Noise

As you know that PWM regulates the fan RPM. In this way, the fan changes RPM based on the need for temperature and eliminates the loud fan noise to a greater extent. While 3 pin fans rotate entirely at high potential by which you will experience much more noise than 4 pin fans.

3. Productivity

CPU fans are always placed on a copper or aluminum heatsink use either a 3 pin fan or a 4 pin fan connector. The conventional 3 pin connectors are designed for small fans with low power consumption. While 4 pin fan connectors are designed for modern CPUs with higher power consumption.

4. Life Expectancy

The life expectancy of 4 pin fans is more than 3 pin fans. This is because 4 pin fans change their RPM and voltage as per the needed for maintaining good temperature of CPU. On the contrary, the 3 pin fan rotates the fans with high potential most of the time.

Thus, a 3 pin fan loses its efficiency sooner than 4 pin fan.

Difference Between 3 Pin and 4 Pin Fan connector

3 Pin vs 4 Pin Fan Connector: Which Should I Get?

Whenever you buying a PC fan, make sure to have a PWM fan rather DC. The future is definitely for a 4-pin connector on the motherboard header. As these PWM fan connectors are much the finest compared to 3 pin fans.

Also, 4 pin coolers are most often used to cool the processor, while conventional fan coolers can have 3 pin connectors. It is not so difficult to guess why this is necessary.


What is the significant difference between a 3 pin fan and a 4 pin fan?

The significant difference in practice is that 4-pin fans allow for RPM to change based on the need for cooling temperature, this reduces noise and power consumption. While 3-pin can control the voltage, but the voltage can’t turn to change the fan RPM at all and accurate as much as 4 pin fans.

Are PWM fans 3 or 4 pin?

PWM fans are always 4 pin fan connectors. The additional wire has the ability to adjust the rotation speed depending on the temperature of the CPU.

Do 3 pin fans do not have control over speed and voltage?

No, 3-pin fans also have their own signal wire, but the speed of rotation of the impeller depends on the change in the voltage of the power cable, although it should be noted that in some cases the speed control is not much accurate and automatic than 4 pin fans.

Is PWM fan better?

Yes, it’s worth getting PWM fans because they are quieter and scale with temperature and much better than others and will be the future of fan connectors. Also, it is recommended to have PWM connectors for cabinet fans on the motherboard.

Can I plug 3 pin fans into 4 pin fan header, will it work?

Yes, you can, most of the 3 pins header motherboard let you work by connecting only 3 pins of the fan. In fact, the 4th pin is just for PWM.

This was the ‘3 Pin vs 4 Pin Fan and its differences‘, it is hoped that the information guided you.

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