Unable to control fan speed via OPT Fan1 header

[Whoopsy]

Currently running Bios 1201 on Rampge IV Extreme

I have 4 of these 120mm fans connected via CHA_FAN 1, 2 and 3 and OPT_FAN 1.

The CHA_FAN headers seem to be working fine.

The OPT_FAN 1 seems to be running at 100% all the time.

I have tried to set its duty to 50% in bios.

I originally thought it was the fan that was the cause of my problem but after trying different fans in OPT_FAN 1, it seems that the header itself is the cause of my troubles.

If I plug the fan in OPT_FAN 2 or 3, fan runs fine and fan speed can be adjusted via bios.

Now I am wondering whether my trouble with OPT_FAN 1 is from a bad mobo or is there an upcoming bios that would fix this issue with the uncontrollable fan speed via OPT_FAN 1 header.

CPU - i7 3930k
RAM - 32GB G.Skill RipjawsZ DDR3-2133 (8x4GB)
MB - Rampage IV Extreme Bios 1201
CPU Cooler - Corsair H100
PSU: Corsair AX1200
SSD - 240GB Vertex3 Max IOPS
GPU - ATI Radeon HD5970
OS - Windows 7 Ultimate SP1 x64
CASE - Corsair Special Edition White Graphite Series 600T

[xeromist]

Not sure. Is that one considered a CPU opt header? It might be considered a pump header that should always operate at full duty? :confused:

[Whoopsy]

Pretty sure that this header was not meant to be run at 100% all the time.

You can see that there is CPU_OPT already at the top right corner.

Maybe someone else on here could try a PWM fan on the OPT_Fan1 Header of the RIVE running BIOS 1201 and let us know whether they can control the fanspeed through the BIOS.

I am still not sure whether it's a bios issue or board issue.

[GuzMonster]

I've noticed OPT Fan3 header is at max fan speed eventhough it is set at custom settings. Max speed is set at 60-70 degrees celsius, and my board's temp is always below 40. I'm on bios 1201 BTW.

[Retired]

The opt_fan1 should not being a prob to control, and the pwr_fan should not be connected to that header...

[mdzcpa]

Whoopsy,

Because the OPT CPU Fan is meant for another CPU Fan, you need to run a 4 pin fan connector in order to regulate speed. I tried the fan header with a 3 pin and a 4 pin fan, and the 4 pin can be regulated, but not the 3 pin. Inconvenient yes, but the header is designed for a 4 pin CPU fan. All the other headers can be regulated with 3 pin fans, but the CPU fan is a no go with 3 pins.



GuzMonster,

Try setting Duty Cycle at 50%. This will cut the RPMs down. Then go back a reset for Temp settings.


To both,

Running 4 pin fan connectors works best and all fans are easily controlled this way. The 4th pin missing on a 3 pin connector is the PWM (pulse width modulation) control pin. Without this the BIOS is only estimating required fan voltage based on RPMs and predetermined voltages supplied at various duty cycles. The 4th PWM pin provides for more acurate speed modulation. Hope this helps.

[Whoopsy]

I am not using the OPT_CPU header at all, the one I am having trouble regulating the fan speed is the OPT_FAN 1.

See my original post.

[Ahmedivx]

mdzcpa wrote:
Whoopsy,

Because the OPT CPU Fan is meant for another CPU Fan, you need to run a 4 pin fan connector in order to regulate speed. I tried the fan header with a 3 pin and a 4 pin fan, and the 4 pin can be regulated, but not the 3 pin. Inconvenient yes, but the header is designed for a 4 pin CPU fan. All the other headers can be regulated with 3 pin fans, but the CPU fan is a no go with 3 pins.



GuzMonster,

Try setting Duty Cycle at 50%. This will cut the RPMs down. Then go back a reset for Temp settings.


To both,

Running 4 pin fan connectors works best and all fans are easily controlled this way. The 4th pin missing on a 3 pin connector is the PWM (pulse width modulation) control pin. Without this the BIOS is only estimating required fan voltage based on RPMs and predetermined voltages supplied at various duty cycles. The 4th PWM pin provides for more acurate speed modulation. Hope this helps.

That was helpful to me, thanks for the info 🙂 I was having this issue with CPU_OPT the main CPU Fan is PWM 4-Pin while the CPU_OPT is 3-Pin, other three Chassis Fans are 3-Pin but I can control them with no issue

I have another question if I may ask, is it possible to add a Fan Hub Extension Card like the one comes with X99 motherboards to add more controllable fans through the board itself, my motherboard is the Z97 Maximus VII Gene

[mdzcpa]

Sorry about that.

I have no idea what the issue might be on your mobo. Mine works okay with a 3 pin. I am using all 3 of my OPT FANs. Sorry I cannot be of more help.

[Raja]

Whoopsy wrote:
Currently running Bios 1201 on Rampge IV Extreme

I have 4 of these 120mm fans connected via CHA_FAN 1, 2 and 3 and OPT_FAN 1.

The CHA_FAN headers seem to be working fine.

The OPT_FAN 1 seems to be running at 100% all the time.

I have tried to set its duty to 50% in bios.

I originally thought it was the fan that was the cause of my problem but after trying different fans in OPT_FAN 1, it seems that the header itself is the cause of my troubles.

If I plug the fan in OPT_FAN 2 or 3, fan runs fine and fan speed can be adjusted via bios.

Now I am wondering whether my trouble with OPT_FAN 1 is from a bad mobo or is there an upcoming bios that would fix this issue with the uncontrollable fan speed via OPT_FAN 1 header.

CPU - i7 3930k
RAM - 32GB G.Skill RipjawsZ DDR3-2133 (8x4GB)
MB - Rampage IV Extreme Bios 1201
CPU Cooler - Corsair H100
PSU: Corsair AX1200
SSD - 240GB Vertex3 Max IOPS
GPU - ATI Radeon HD5970
OS - Windows 7 Ultimate SP1 x64
CASE - Corsair Special Edition White Graphite Series 600T

Have you got a temp probe plugged into the temp probe header next to OPT_FAN1. If yes, what is it attached to?