Question Thermaltake Core1 3-pin system fan control with Biostar B150GTN mother board 4-pin fan header

[mcroft]

I've plugged in the 200mm 3-pin system fan to the 4-pin header and the fan works at full-speed only. In the bios there is the option to set fan control for the system fan but the options are "Disabled" or "Auto". Auto seems to use PWM and there doesn't seem to be a way to specify voltage control and after studying the forums I assume that I need to change my fan to a 4-pin PWM.

Would a fan controller allow the motherboard to control the 3-pin fan? How would this work? Would the controller convert the PWM signal sent on the 4th pin and modify the voltage on the relevant pin on the controller fan header? Or am I misunderstanding?

 

[Traditore]

There is no PWM signal to convert because you won't use 4th motherboard pin. 3pin fan speed is controlled by changing voltage. Set 'auto' and plug the fan. See if fan speed is registered in BIOS.

 

[mcroft]

Yeah, I've already set SmartFan function to Auto - it was disabled by default. The fan speed shows as about 800rpm.

So if, as I suspect, the mobo system fan header doesn't support voltage control, is there any way to control the current fan? I thought the controller would plug into the 4-pin header and somehow allow the fan connected to the controller to operate in voltage mode. But I don't understand this stuff - I've seen other posts suggesting a controller would fix the problem. I just don't understand how or if this is possible in my scenario.

 

[Paperdoc]

OP, you are quite correct. And no, a third-party Fan Controller will NOT solve your problem the way you want. Third party Controllers almost never try to connect with the mobo in any way - they are completely separate units that allow YOU to set and change fan speeds, and most will display those speeds. BUT they do NOT know anything about mobo or CPU temperatures and they cannot access control signals form any mobo header. YOU are the Controller, really - you must decide what speed any fan should be, and when to change it.

You are correct also in diagnosing the constant full speed problem. Your mobo''s SYS_FAN header only can use the newer PWM Mode, and that cannot control the speed of the older-design Voltage Controlled (3-pin) fan type. Your proposal to change the fan to a 4-pin type is the easiest solution. The alternative, but maybe more expensive, actually does what you were hoping a Controller would do. The Phanteks PWM Hub is a fan HUB used to connect many fans to a single header and draw fan power from the PSU directly. But unlike almost all other Hubs, the Phanteks model does convert from the 4-pin PWM Mode supplied by the mobo header into six 3-pin output ports that all use only the older Voltage Control Mode to control its fans, and that is what a 3-pin fan needs. You may find the costs of either this Hub or a replacement 4-pin fan similar. The only advantage of the Hub would be IF you believe you might want to add more fans to your system.

 

[mcroft]

Thanks for the advice. I see that the Phanteks PWM hub is around £16 on Amazon whereas the cheapest 200mm PWN fan I have seen is around £25 (Noctua). So I might go for the hub. Thanks again for your information.

 

[Paperdoc]

You're welcome.