When building a PC, connecting the front headers and fans to the motherboard can be stressful.
The good thing is you’ve got the option to go with eitherCPU FANorOPT FANheader.
So, lets get started.
What is CPU FAN and OPT FAN?
TheCPU_FANis the primary fan header for your CPU cooler.
If you use an air-based cooler, this is where it’s crucial that you connect the CPU fans.
The headers provide the BIOS with the information that a cooler is connected.
Once that is detected, the PC can fully power on.
For your reference, this is what the headers would look like on your motherboard.
How to connect all these fans then?
Thats when theOPT_FANcomes into use.
Some people also call it the optional header.
you could connect the AIO pump to this header.
The rest of the cooler fans can then connect to the CPU FAN header.
While essentially the same thing, theCPU and case fans are quite different.
Check our separate article where we discuss these differences and how to properly use one.
However, it’s possible for you to stillreplace the CPU fan with a case fan.
What are the Different Fan Headers on your Motherboard?
Apart from the aforementioned fan headers, there are additional ones present.
These are mainly used for connecting your case fans.
The 3 pins fan headers areDCcontrolled and come with fixed fan speed as configured.
Now lets look at all the fan headers that you get.
Functionality wise the system and chassis fan headers do the same thing.
The naming scheme varies from one motherboard to the other.
If you connect your fans to either of them you will be fine.
Want to know if yourCPU cooler is working properly?
When to use CPU FAN vs OPT FAN?
Lets answer this question by considering the jot down of CPU cooler that you use.
Sometimes your cooler may employ the dual fan design such as the Noctua D15.
One to power the pump and the other to the radiator fan.
Furthermore, you might have up to three CPU cooler fans connected to the radiator.
So, four headers in total.
In this case, connect the AIO pump to theCPU OPT.
Connect all the radiator fans to the same fan splitter and then connect it to theCPU FANheader.
This will give you the ability tomanually control the fans speedusing the motherboard or any third-party software.
Frequently Asked Questions
Can I put a case fan on CPU OPT?
But it’s advisable to plug in the case fans to their dedicated headers instead.
How to control CPU OPT fan speed?
Next, go to the BIOS and open up the manufacturer-specific software such as Q Fan for ASUS motherboards.
Here it’s possible for you to change the fan curve and its speeds.
Can I plug a 3-pin fan into a 4-pin?
you’ve got the option to actually plug a 3-pin fan into a 4-pin.
But in this way, you will lose the PWM functionality.
You will no longer be able to control the fans speed using software such asSpeed Fan.
The fan will then run inDC modeat 100% speed all the time.
In Conclusion
The optional CPU header makes it convenient to connect your CPU radiator fans.
Otherwise, the vanilla CPU fan header is perfectly fine for you.
This should solve your dilemma regarding the fan headers.
So go ahead and plant the cooler.
And get the PC ready for some feel-good gaming sessions.
