The motherboard has specific pinouts for various fan connectors, such as the CPU fan, System fan, and Case fan connectors. Below are the pinouts for each type:
1. CPU Fan Connector (4-Pin or 3-Pin)
The CPU fan header is typically a 4-pin or 3-pin connector, with the 4-pin version allowing for more advanced speed control (PWM).
4-Pin CPU Fan Pinout:
| Pin | Function |
|---|---|
| 1 | Ground (GND) |
| 2 | Power (12V) |
| 3 | Tachometer (Fan Speed) |
| 4 | PWM (Pulse Width Modulation, for speed control) |
3-Pin CPU Fan Pinout:
| Pin | Function |
|---|---|
| 1 | Ground (GND) |
| 2 | Power (12V) |
| 3 | Tachometer (Fan Speed) |
2. System Fan (SYS FAN) or Case Fan Connector (3-Pin or 4-Pin)
Similar to the CPU fan header, system or case fan headers can either be 3-pin or 4-pin connectors.
4-Pin System Fan Pinout:
| Pin | Function |
|---|---|
| 1 | Ground (GND) |
| 2 | Power (12V) |
| 3 | Tachometer (Fan Speed) |
| 4 | PWM (Pulse Width Modulation, for speed control) |
3-Pin System Fan Pinout:
| Pin | Function |
|---|---|
| 1 | Ground (GND) |
| 2 | Power (12V) |
| 3 | Tachometer (Fan Speed) |
Key Notes:
- The 3-pin fans are controlled based on voltage (i.e., their speed depends on the voltage provided), whereas the 4-pin PWM fans are controlled via a signal to modulate fan speed.
- The tachometer pin (usually pin 3) provides the fan speed signal, which the motherboard uses to monitor and adjust the fan speed.
- Some modern motherboards feature fan headers that automatically detect whether you’ve plugged in a 3-pin or 4-pin fan, adjusting control accordingly.
This pinout is common across most motherboards, though it’s always a good idea to consult your motherboard manual for the exact pinout, as it may vary slightly between different models.
