3 pin vs 4 pin fan cables: Differences, Which is better

When building or upgrading your PC, one of the more important decisions you need to make is which fans will cool your case. Modern computers use high-performance internal components that become incredibly hot during operation.

To keep these temperatures at a reasonable level, it is necessary to install some case cooling fans. However, different types of case fan connectors are available on the market. These three pin and four pin fan cables may seem like minor details, but they can significantly influence the performance of your computer system as well as its compatibility with other components (motherboard, graphics card external ports). That’s why we decided to publish this tutorial explaining how 3 pin vs 4 pin fan cables work and what are their benefits/downsides.

3 Pin Vs 4 Pin Fan

main differences between 3 pin vs 4 pin fan:

A 4 pin system fan power supply connection has an additional wire that carries information about the rotational speed of the fans. There are also cases where specifying only the voltage – as in 3-wire – does not give enough information to control the rotation speed of the system fan and this extra wire provides another way to do it.

3 Pin Fan Cable/Connector Specification Details

The 3-pin connectors come with two voltage wires (+12V and GND) and one PWM signal wire. A 4-pin connector has three voltage wires, one PWM signal wire and an extra RPM wire for the fan speed reading. This means that a 3-pin cable can control the system fan’s rotational speed by changing the voltage between 0% and 100%. On the other hand, a 4 pin cable can change both voltage and PWM duty at any percentage in between, allowing more precise control over fan speeds.

3 Pin And 4 Pin Fan Cables: How Do They Work

A 3 pin case (or system) fan power supply connection is enough when no information about the rotation speed of the fans is needed. The motherboard software may control all types of fans without problems; it only needs to know if they are running at full speed or not. However, these 3 pin and 4 pin fan cables can determine your case’s cooling performance and the noise generated by the fans:

3 pin vs 4 pin motherboard fan control

As we mentioned earlier, a four-pin system fan power supply connection has an additional wire that carries information about the rotational speed of the fans. This way it becomes possible to adjust their speed more precisely than with just voltage manipulation. For example, you can use software to lower the rotational speed of your system fans according to the processing load; this will make them run much slower without using much less power (since they are still receiving 12v). If you connect a four-pin system fan connector to a dedicated controller like our Commander FP, you can monitor the temperature in your case and control your system fans by raising their rotation speed when needed.

3 pin fan vs 4 pin fan: what is better

The main advantage of using 3-pin or 4-pin fans is that they are usually cheaper than their 5-pin counterparts; however, there are one or two drawbacks which you need to be aware of before buying them (we will explain these later). The significance of having more precise control over the rotational speed, in combination with PWM technology in motherboards and dedicated controllers/sensors, cannot be overlooked. However, this does not necessarily mean that 3 pin vs 4 pins fans are incompatible; after all, most modern motherboards come equipped with 4pin headers, but not all of them are used to their full potential. If you only use the first 3-4 pins in your motherboard for case fans, it is better to buy a 4 pin fan cable, even if this means sacrificing some performance. This way you will avoid problems when upgrading or changing your system fans in the future.

3 pin vs 4 pin fan Pros and cons

3 pin fans are cheaper than their 4-pin counterparts. They have less wire and components, which makes them lighter, cheaper to produce and easier to transport. Sometimes it is hard to find matching 4-pin fan cables for PWM system fans; this does not happen with 3 pin models.

4 pin fans are more precise at controlling the rotational speed of the system case fan. This means that they are ideal for use with motherboard/Dedicated controller PWM technology ( read our dedicated tutorial on how PWM works ). Many people prefer using high RPM (and therefore loud) case fans, because low duty cycles do not let them experience game sounds properly; however, these types of fans can irritate you over time by creating too much noise. Using PWM technology will let you use your fan’s full potential (no matter how high it is) while keeping the noise level to a minimum.

When do you need to buy a new fan cable?

3 pin fan connectors were the standard for a long time, but they can’t keep up with modern cooling devices. A new generation of fans requires a 4 pin connector to provide the best performance possible. If you have a well-performing chassis cooling system already installed in your computer and it doesn’t seem to be overheating, then you don’t need to invest into a new 4 pin fan cable. However, if your case fans aren’t stopping even when the system is idling or if you plan on installing more advanced PC components that require better airflow (overclocked CPU, graphics cards running at maximum load), then investing into an upgraded case fan solution seems like a smart choice.

How do I know if my computer has a 3 or 4 pin connector on the motherboard?

Most modern motherboards come with 4 pin connectors. If you don’t want to open your PC case, you can quickly determine whether this is the case by just looking at the fan cable coming out of it: if it has four pins, then chances are that your motherboard features a 4 pin fan connector. It’s possible that the system only works with three-pin fans (motherboard manufacturer might have used cheaper components) in which case you can still use our tutorial and make your 3 pin fans compatible with 4 pin motherboard ports . All you need is a simple adapter .