Help me with fan speed

darkenvy

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Aug 4, 2012
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Guys,

First time post for me but I didn't know where else to look.
I have just put together a new system with a GA-Z77X-UD3H motherboard. The motherboard comes with 4 system fans plus 1 for the CPU. I have a Cooler Master case with 4 fans plugged into each of those 4 fan headers. For some reason all fans except SYS-FAN3 run at normal RPMs whereas the side fan plugged into SYS-FAN3 socket runs at 100% from the get go. I have no idea why that's happening even when the machine is stone cold ? Is it something I can set / control ?

Thanks
Rod
 

raytseng

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May 15, 2012
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this depends on your mobo.
Often some of the fan controls on the mobo are uncontrollable and just run at full speed. sorry i am just guessing since i don't have your mobo. So I don't know if this is truly correct for your mobo.
If you don't see it in bios, or in any utilities provided with your mobo, you are out of luck.

If you do not have any fan controls on your mobo for some of the fanheaders, then your options can be to makeup an adapter to control the power to that fan.

Different ways to do this. You can completely separate away from the mobo; using fixed voltage by attaching wires to molex at spliced at the right voltage combo.
or buying certain adapters or controller to help you with this.

Or if you still want to power from your mobo, there are controller adapters you can stick inbetween to adjust the speed; or you can splice the wires together to another fan sharing 1 header that you can control.
 
G

Guest

Guest

1st/2nd/3rd System Fan Speed Control (SYS_FAN1, SYS_FAN2 and SYS_FAN3
it it to man in the bios then under it go to slop pmw and change that fan speed setting.
the bios has two setting one for three pin (power) control of a fan.
and pmw for the 4 pin type fans.
 

darkenvy

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Aug 4, 2012
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10,510
The BIOS allows me to set the ratio for my system fans which applies equally across SYS_FAN1, SYS_FAN2 and SYS_FAN3.

My case fans (all 3-pin) are plugged into SYS_FAN1, SYS_FAN2 and SYS_FAN4 and they all run at different RPMs. It's when I plug a 4th fan into SYS_FAN3 (which should be controlled by the BIOS) that's when the RPMs shoot up

Should I re-route my connections to different SYS_FAN ports to experiment ? Surely that's not ideal