This library provided by MiniTool will introduce you mainly to three types of heatsink headers: CPU OPT, CPU fan, and case fan (SYS fan), as well as compare CPU fan with CPU_OPT.
About CPU Fan Header
To learn what does CPU OPT mean, first of all, you need to know what is a CPU fan header.
According to the answer on Quora, most computers have a CPU and a heatsink mounted on top of the CPU with a fan. A CPU fan header is where you plug the fan. The CPU fan header is important for it can detect whether your fan is working or not. If it detects the fan isn’t running or is not working properly, it will close the system or stop the system from starting to protect the computer from overheating.
What Is CPU OPT?
CPU opt meaning is CPU optional. It is a header that is used to connect some type of wiring for a liquid cooling system. Once connected, you are able to control the speed of the fan from the motherboard.
Most gaming motherboards are equipped with such CPU OPT for controlling the heat sink speed. when you aren’t using the PC for heavy load, you can reduce the fan speed so as to reduce the noise of your system.
Some heatsinks may pair with 2 fans or may have clips on both sides. In such a situation, one fan pushes cool air into the fins while the other fan pulls hot air out.
In general, CPU OPT is an additional CPU fan header. Since it is “additional”, it is not necessary and the system can start normally without working with CPU_OPT. that is to say, CPU OPT can’t prevent the system from booting if there is a problem. Yet, it can warn you about problems.
CPU Fan vs CPU OPT
Both CPU fan header and CPU OPT fan connecter are heatsink headers for connecting the fans of radiators on the motherboard. The difference is that the CPU fan header can detect fan problems and protect the system from overheating by preventing it from booting. While the CPU-OPT and only detect and warn about issues; it cannot take actions to deal with the problems.
Case Fan
As the name indicates, a case fan is a kind of fan used to cool the case or enclosure of the computer host. There are other names for this type of cooler like SYS fan. As for the brand Asus, it calls it a chassis fan or CHA-FAN.
Similar to CPU OPT, a case fan can inform you if there is a problem with the fan, but can’t protect the system from overheating by stopping it from booting up.
Also read: Introduction to Computer Fan Including Applications
Can I Use CPU OPT for Case Fan?
CPU fan header, CPU OPT, and SYS fan header, if all of them are 4 pin fan headers, the motherboard, and in turn the BIOS and the OS, can control the fans’ speed. therefore, theoretically, you can connect the case fan or one of the case fans to the CPU OPT without a problem.
However, if you connect your case fan with the CPU opt header, the speed of the case fan will increase dramatically when the CPU gets hot, just like the heatsink/CPU fan connected to the CPU_FAN header will do. And, when the CPU cools down, the case will slow down.
While if you connect the case fan into the SYS_FAN header, it will change its speed accordingly by the signal coming from the thermal sensor or some software controlled by the BIOS or the OS.