CPU_OPT and CPU_FAN are motherboard connectors that keep your CPU cool.
The CPU_FAN connector is for your main cooling fan, giving you solid thermal management right out of the box.
The CPU_OPT connector is for extra cooling stuff. You can use it for additional fans or water cooling modules where pumps are needed.
| Feature | CPU_FAN | CPU_OPT |
| Primary Usage | Primary CPU cooler fan | A secondary fan or pump |
| Control Type | Primarily PWM (focused on CPU temp) | Often PWM or DC (flexible use) |
| Voltage Output | Typically 12V | Typically 12V |
| Fan Speed Control | Directly tied to CPU temperature | Can mirror CPU_FAN or operate independently |
| Ideal for | Main CPU cooling | Auxiliary fans, water cooling pumps |
| Motherboard Presence | Standard on all motherboards | Optional, not always present |
| Real-Life Example | Cooler Master Hyper 212 Evo (air cooling) | Corsair H100i pump (liquid cooling) |
| Compatibility Considerations | Universally compatible with motherboards | Check the motherboard for availability |
CPU_OPT vs. CPU_FAN: Key Differences
Let us now track the OPT and FAN differences from a more analytical perspective:
Primary Functions
CPU_FAN is where you plug in your main cooling fan. It’s not just a connector; it’s the lifeline for your CPU, ensuring it doesn’t sweat under pressure. No fan here? Expect your motherboard to throw a fit.
Then comes the cool flex – Optional but oh-so-flexible, the CPU_OPT connector is your go-to when you want to jazz up your cooling game.
- Thinking of adding a pump for a water-cooled setup? CPU_OPT is your buddy. It’s there to handle the extras, so your CPU doesn’t lose its cool.
- Big Radiator? No Problem! Hook the pump to CPU_OPT and let the fans chill on the CPU_FAN connector. This way, everything stays frosty even when the gaming gets hot.
Why Bother?
If you’re building a rig that’s more loaded than a double cheeseburger, ensuring both these connectors are in play is crucial.
They’re like the dynamic duo of cooling—keeping your gaming or creative sessions interruption-free.
Control Type
When building your PC, the term “PWM” pops up like a pop quiz—surprising and boring but important.
PWM stands for Pulse Width Modulation and both CPU_FAN and CPU_OPT connectors support it.
Here’s why it’s cool (literally):
- Smart cooling: Too hot? Fans speed up. Chilling out? Fans slow down. It keeps your PC cool without breaking a sweat.
- Energy saver: It’s eco-friendly too, using just enough juice to keep things cool, so your energy bill won’t spike.
With PWM control, your fans are always in sync making sure your PC’s cooling is as smooth as your latest Spotify playlist.
When to Use?
If you plan on setting up a basic rig first, the CPU_FAN is your go-to connector. The CPU_OPT connector should only be used if your rig or the assembled PC requires an additional cooler, say an AIO cooler for that matter to improve the overall efficiency.
What if There’s No CPU_OPT?
If your mobo doesn’t have support for CPU_OPT like the GigaByte B450 AORUS Elite. In that case, it is better to keep your rig-based ambitions limited as you would then not be able to handle a lot of gaming and content-creation bandwidth.
As for real-life examples, coolers like the Cooler Master Hyper 212 Evo can fit into the CPU_FAN connector as it is often used as the main CPU fan.
Advanced picks like the air cooling dual-fan unit, Noctua NH-D15, can pair with both CPU_FAN and CPU_OPT, one fan for each.
Therefore, before you pick the right set of fans, check the CPU motherboard compatibility and how many connectors are offered by the motherboard manufacturer.
Voltage
Whether you plug your cooler into CPU_FAN or CPU_OPT, both connectors supply a standard 12 volts.
This consistency means you don’t have to play a guessing game with your equipment.
Whether it’s a basic single fan setup or a more complex dual fan system, 12V ensures that all standard cooling gear gets the power it needs without the risk of under or over-voltage issues.
Fan Speed
To explore the fan speed element, you need to locate the motherboard settings and make a few adjustments.
You can either set a fixed speed or adjust the fans and radiators to dynamically provide more or less cooling depending on the changing CPU temperature.
Pro tip: If you still want to use a multi-fan setup on a motherboard that lacks CPU_OPT using splitters can do the trick. (However, this kills off individual fan control.)
SYS_FAN and CHA_FAN
If you want to give equal attention to case-specific fans, which help with airflow and ventilation, you need to know about the SYS_FAN and CHA_FAN motherboard connectors.
While the CPU_FAN and CPU_OPT connectors are specifically meant for cooling the CPU, the SYS_FAN (system) and CHA_FAN (chassis) connectors are meant for the entire rig and help with circulation.
Their performances are independent of the CPU’s temperature fluctuations.
