X4 fan speed control

#1

Hello
My copy of the X4 arrived today with dedicated case/fan. Everything looks OK, but I noticed that the mounted fan always runs at maximum speed when the unit is turned on. I also didn’t find any option in the BIOS to control this. How do I control the speed of the fan? On maximum speed the fan is very loud.

#2

I’m afraid it’s not possible to control the speed as the fan only has 2 wires. The fan is just connected to 5V and GND

#3

It’s a pity, really. This doesn’t make the case very useful.

#4

An option would be to use a different fan that has speed control and use the RP2040 to control the speed

#5

It IS POSSIBLE to change fan speed with 2 wires 5V setup, it’s done with voltage change or PWM,
Same idea is used in many other boards like ROCK 5B,

#6

Could someone from @Radxa team comment on this issue? Is there any BIOS update planned to enable fan control? From the hardware side, is it even possible?

#7

From the hardware side, it’s impossible. The fan on the buttom of Radxa X4 board has just two wire, one is vcc and one is gnd, so the fan can’t be controled by software.

#8

X4 CPU fan directly connect to P5V_S, you can not control this 2 pin.
However, 2 pin is possible to change fan speed via pwm without smart fan sensor. you can try make some additional board and use RP2040 PWM to control it.