system fan trouble

[odylong]

Hi I have a msi z87 g43 mobo and I've got 3 system fans in my case

 

two of them behave normal , but after I overclocked my cpu , one went into overdrive mode ... the first two fans are spinning at 920RMP but the 3rd one is spinning at 1250 RMP and I quite noisy.

 

So I went into my bios and check the hardware monitor and tried to change the max fan speed on the system 3 fan but this didn't affect the fan speed at all ... what's also weird is that it keeps jumping between 1250 RMP and 19000 RMP ... which obviously can't be normal... pls help

 

also they're connected with 3 pin connectors

[odylong]

guys pls halp

[ross06187]

is the 3rd fan in the CPU header on the motherboard?   (some have 2 cpu headers)  as overclocking increase temp, that would make that fan run faster

 

On a side note most bios's have half decent fan control have  play with it.

 

guys pls halp

[cesrai]

Maybe a bug.

[kei7t9]

As what Ross mentioned.

 

Also try to check what fan header that 3rd fan is connected to. Normally if its connected to the CPU Header (4-Pin which also supports 3 pin fan), a CPU header is a true PWM. So depending on how hot your CPU goes when your OCing. The mobo will automatically crank up the fan connected to the CPU fan header to try and cool it down. 

 

As for the rest of the fan header's found on the motherboard, they are usually controllable through your UEFi Bios normally Silent Mode > Standard Mode > Performance Mode > Max Yolo Mode (jk on the last one) but ye Max Fan speed mode.