And while the printed labels can help you navigate the motherboard, they aren’t exactly descriptive.
For example, what does CPU_FAN and CPU_OPT even mean?
Use CPU_FAN for Your CPU Cooler
The CPU_FAN (also CPUFAN, CPU_FAN1, etc.)
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header on your motherboard is afour-pin fan headerthat your gear uses to power and control the CPU cooler.
It’s usually found on the right side or above the CPU socket.
Almost every motherboard has this universal header, and nearly every CPU cooler uses it.
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However, you canchange the CPU fan temperature input in the BIOS.
Using a Y-splitter to connect two fans to the CPU_FAN header may also result in a CPU fan warning.
CPU_OPT Is for a Second Cooler Fan
CPU_OPT (also CPU_FAN2, etc.)
CPU_OPT has only three pins on some cheaper motherboards, which means it can lack PWM fan control.
The CPU_OPT header is usefulif you have an aftermarket coolerwith two fans.
Like CPU_FAN, CPU_OPT changes the fan speed based on the CPU temperature.
you might connect either a three-pin or four-pin fan to the CPU_OPT header, as they’re interchangeable.
The header’s location is handy if you want to add a fan at the top of your case.
A Y-splitter on the CPU_OPT header won’t be an issue, provided your motherboard can handle the load.
What About SYS_FAN and CHA_FAN?
SYS_FAN stands for “system fan,” and CHA_FAN is “chassis fan.”
They can be either three-pin or four-pin headers, and they’re interchangeable.
