Cpu_Fan1, Pump_Fan1, Sys_Fan1~4: Fan Connectors; Jtbt1: Thunderbolt Add-On Card Connector - MSI X299 TOMAHAWK User Manual

CPU_FAN1, PUMP_FAN1, SYS_FAN1~4: Fan Connectors

Fan connectors can be classified as PWM (Pulse Width Modulation) Mode or DC Mode.
PWM Mode fan connectors provide constant 12V output and adjust fan speed with
speed control signal. DC Mode fan connectors control fan speed by changing voltage.
When you plug a 3-pin (Non-PWM) fan to a fan connector in PWM mode, the fan speed
will always maintain at 100%, which might create a lot of noise. You can follow the
instruction below to adjust the fan connector to PWM or DC Mode.
Important
You can switch between PWM mode and DC mode and adjust fan speed in BIOS
> HARDWARE MONITOR. And please make sure fans are working properly after
switching the PWM/ DC mode.
Pin definition of fan connectors
PWM Mode pin definition
1 Ground
3 Sense

JTBT1: Thunderbolt Add-on Card Connector

This connector allows you to connect the add-on Thunderbolt I/O card.
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Overview of Components
Auto-detection Mode fan connectors
2 +12V
4 Speed Control Signal
1
3
5
1
CPU_FAN1/ PUMP _FAN1
1
SYS_FAN1~4
DC Mode pin definition
1 Ground
3 Sense
1
FORCE_PWR 2
SLP_S3# 4
Ground
2 Voltage Control
4 NC
SCI_EVENT
SLP_S5#