Difference Between Sys Fan Vs CPU Fan (Full Comparison)

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In the given article, we’ll discuss the differences between Sys Fan Vs CPU Fan. I hope this will be very useful for you.  A CPU fan is a fan that is mounted on top of a CPU. It cools the processor by sucking and blowing warm air away from it. A fan within a power supply is known as a power supply fan. The power supply fan exhausts hotter air from the power source and the computer.

Sys Fan Vs CPU Fan

The primary distinction between System and CPU fans is that the former is used to ventilate the PC case or chassis, whereas the latter is utilized to cool the CPU. For your desktop PC to have the proper ventilation installed, you must understand how the two differ.

Difference Between Sys Fan Vs CPU Fan


The CPU Fan header does precisely what it says on the tin. A conventional PC has a single CPU with a heat sink and fan installed on top of it. That is where the fan would be plugged in. That header is significant because it determines whether or not your fan is operating.

To prevent your CPU from overheating, it will shut down (or refuse to start) your system if it recognizes the fan is not functioning or not running properly. CPU OPT is an acronym for CPU Optional. This is often the header used to attach some form of cabling for a water-cooling system. For example, my liquid cooling system is powered by two pumps (two separate loops).

I can plug a single wire from each of these pumps into the Processor OPT header. This is a feature I don’t utilize because I prefer my conditioning pumps to operate at maximum speed. However, if I plugged those connections into the motherboard, I’d be able to adjust the pump’s speed from the motherboard, which leads me back to the CPU FAN.

The velocity of the heat sink fan linked to the CPU FAN header on most gaming motherboards can be controlled. The rationale for this is that if your computer is not under heavy demand, you can lower the Fan Speed Control and therefore lessen the amount of noise produced by your system.

Fan For The System

SYS FAN is known by several different names. They’re known as chassis fans, or CHA-FAN, by Asus. Other motherboards have referred to them as case fans. These are the headers that you use to connect in the fans that cool you enclose or case, regardless of what you call them SYS FAN.

This is for a box fan or overall system fan that blasts warm sluggish air out of the case and maintains airflow. Not having a fan attached to the SYS FAN header, like CPU OPT, will not stop the system from operating, but it will notify you if the fan is malfunctioning.

If these are 4 pin fan headers, the motherboard, and thus the BIOS and OS, can control the Speed Of The Fans, so you could theoretically connect the case fan (or one of the case fans) to CPU OPT with no problem.

However, a case fan connected to the CPU OPT header will ramp up in speed when the CPU gets hot, just like the CPU/heat sink fan connected to the CPU FAN header, and will slow down when the CPU is adequately cooled, whereas the (and on the operating system side, either the operating system or some third-party software)

Major Difference Between Sys Fan Vs CPU Fan

The key difference is that CPU FAN is the connector for the CPU cooler’s primary fan. Because certain coolers contain two fans (one push, one pull), the CPU OPT allows for the second fan to be connected.

Any fan in the boxes that you want to attach to the motherboards so that it is controlled by the BIOS can be used as SYS FAN. For these fans, there are options for velocity control and alerts in the BIOS settings. Make sure the relevant alert is disabled if you haven’t utilized the CPU OPT or the SYS FAN connection.

When your pc keeps buzzing from the minute you turn it on and you can’t figure out why it’s probably so because the BIOS monitor isn’t getting a speeding signal from that specific connector and guesses the fan is stopped or stalled.

What Is A System Fan?

To cool the computer’s hot circuitry, particularly the CPU, the computer fan’s job is to draw cooler air into the device. A desktop computer’s power supply generally has a fan that draws air through it to keep that portion of the computer cool.

How Many SYS Fans Are On The Motherboard?

Your computer’s motherboard will determine this. Most motherboards feature two connections or more. One will house the processor, while the other will house the case fan. High-end motherboards may support six fans or more.


Between the two varieties Sys Fan Vs CPU Fan, there isn’t much of a distinction. The various titles usually refer to the motherboard’s standard settings for alarms and fan speeds, as well as the simplicity of reading fan speeds using the software.

For example, SYS FAN5 doesn’t tell you where the fan is connected, but it does tell you that it’s probably a case fan, whereas the fan speed trying to read labeled as CPU FAN is almost always the CPU HSF.

The CPU FAN header is normally allocated for the CPU heat sink fan, and if the speed value on this header is 0, most motherboards would either sound an alert or instantly shut down the machine. The fan header SYS FAN is normally allocated for case fans. As case fans are frequently optional, these headers normally do not contain any alarms connected with them by default.

Frequently Asked Questions

Is the SYS fan similar to the CPU fan?

The difference between a CPU fan and a systems fan is that the first is attached to the processor’s heat sink, while the latter is usually located on one of the case’s sides to vent hot air.

Is the SYS fan designed for case fans?

The SYS Fan ports on a motherboard are for use with box fans. One or both of the Bios screens will also allow you to alter the fan speeds.

What exactly is the purpose of the system fan?

Any fan used for energetic cooling inside or attached to a computer casing is referred to as a computer fan. Cooler air is drawn into the case from outside, warm air is expelled from inside, and the air is moved along a heat sink to cool a specific component.

Is it necessary to have a system fan?

The CPU becomes extremely hot as a result of the high pressures and heat, and it is the CPU fan that allows the CPU to function correctly under these conditions. The CPU fan is required to keep things cool and provide them with enough air to cope with the circumstance.

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