I ran into an issue with the plug-in IPMI Support fan control and figured out how to resolve it.

 

I replaced my Supermicro X10SL7-F with an X10SRL-F and the fan speed wasn’t working properly.  Every time the plug-in would poll the temperatures and adjust the fans, it would adjust them then would immediately ramp back up to full speed.  I tried everything, reconfiguring the fans and what headers they were plugged into, checking and double checking the BIOS, etc.  

 

SOLUTION: Log into the Supermicro IPMI web interface.  You need to log into the BMC/IPMI web interface and choose Maintenance > Unit Reset > Reset (click on the reset button to reboot the IPMI device).  After I performed that reset, all of the PWM fans responded properly to the IPMI Support/Fan Control configuration.  

 

Additionally, most tell you how to use impitool (nerd tools) to define the low and high for the fans.  I highly recommend using the IPMI Support plug-in to edit the sensors file (Settings > IPMI > Config Editor > Sensors).  Put in your values that match the fans you’re using.  If you’re using lower spinning fans, the default values will start throwing errors for the fans going low.  For instance, my Noctua PWM fans can run as low as 300 RPM but with the default values of the sensors file, it would cause errors for the fans going low non critical and critical because the low values are set too high by default.  

 

 

Thanks for your guide - appreciate it!

 

I still have a problem with my setup, though - maybe you have an idea?

I recently upgraded to a Supermicro H12SSL-I and connected various fans:
- 1 x bequiet! Silent Wing 2 PWM
- 2 x Noctua NF-A14 PWM
- 1 x Noctua NF-F12 PWM
- 1 x Noctua NF-A15 (CPU-Cooler) PWM
- 3 x Fractal Design (incldued in the case, 3-PIN, so no PWM, I know I can't control them)

 

I'm struggling with this configuration. I have the same problems you had: If I set the fan configuration to any other than "Full Speed" via BMC/IPMI Web UI, the fans decrease the speed as temperature is not high enough but the BMC increases the speeds again as the Lower Critical Threshold is set to 420 and the fans go down to 280 RPM by themselves.
I installed the IPMI plugin and set the speeds and configuration accordingly. But it seems that this plugin just sets the fan configuration to "Full Speed". The fans are always on Full Speed with this plugin and it doesn't dial down the fans speeds.
I did several Unit Resets via IPMI WebUI and also reset the system to factory defaults. Unfortunately no success.

Also I tried to set the the LC Threshold to 280 or 140 - but the board seems to just ignore these manually set values. The new values are shown on the IPMI WebUI but the BMC still throws the "Critical" sign if the fan's speed is below 420 RPM.

 

Do you have an idea what I could do?

7 hours ago, CyberDev said:

Thanks for your guide - appreciate it!

 

I still have a problem with my setup, though - maybe you have an idea?

I recently upgraded to a Supermicro H12SSL-I and connected various fans:
- 1 x bequiet! Silent Wing 2 PWM
- 2 x Noctua NF-A14 PWM
- 1 x Noctua NF-F12 PWM
- 1 x Noctua NF-A15 (CPU-Cooler) PWM
- 3 x Fractal Design (incldued in the case, 3-PIN, so no PWM, I know I can't control them)

 

I'm struggling with this configuration. I have the same problems you had: If I set the fan configuration to any other than "Full Speed" via BMC/IPMI Web UI, the fans decrease the speed as temperature is not high enough but the BMC increases the speeds again as the Lower Critical Threshold is set to 420 and the fans go down to 280 RPM by themselves.
I installed the IPMI plugin and set the speeds and configuration accordingly. But it seems that this plugin just sets the fan configuration to "Full Speed". The fans are always on Full Speed with this plugin and it doesn't dial down the fans speeds.
I did several Unit Resets via IPMI WebUI and also reset the system to factory defaults. Unfortunately no success.

Also I tried to set the the LC Threshold to 280 or 140 - but the board seems to just ignore these manually set values. The new values are shown on the IPMI WebUI but the BMC still throws the "Critical" sign if the fan's speed is below 420 RPM.

 

Do you have an idea what I could do?

Sounds like you might need to use IPMITool to reset your values.  Do you know what your lower threshold is for your fans?  You’ll need to figure out how low you can run them and use IPMITool to set that in the BMC so it doesn’t freak out and ramp them up to full power.  I set mine to correspond to my different fans in the system.

 

2 hours ago, prongATO said:

Sounds like you might need to use IPMITool to reset your values.  Do you know what your lower threshold is for your fans?  You’ll need to figure out how low you can run them and use IPMITool to set that in the BMC so it doesn’t freak out and ramp them up to full power.  I set mine to correspond to my different fans in the system.

 

Thanks for the reply!

 

Is resetting with IPMITool the same as resetting to factory defaults via BMC/IPMI WebUI? If so, than I already did this several times, unfortunately without success.

Afaik the LCT for the Noctuas are 280 RPM - this is at least the value to which the fans briefly jump by themselves.
By default the LCT is set to 420 RPM with a hysteresis of 140 RPM in both directions. I don't know if there is a correlation between the LCT and hysteresis as 420 RPM - 140 RPM = 280 RPM. But this could also be just a coincidence.

In the meantime I got an answer from the Supermicro Support:

Quote

 

...
What might also work for you is to remove the power from the system, disconnect all your fans, make sure the BMC heartbeat LED has stopped blinking, then turn the system on and wait for IPMI to fully initialize. With the fans disconnected IPMI should treat this as expected and should not monitor the fans. Once IPMI has initialized you can then connect your fans again, the fan control should work, but you cannot monitor the fans.

This is also not recommended, but may be a work around for this.

Note that 3-pin fans are notorious for causing fan control issues on our boards, this might also be mitigated by not monitoring the fan headers.

Lastly, you can remove sensors from IPMI with the below commands. They should come back with a factory reset.

How to disable IPMI Sensors:
Use IPMICFG (ftp://ftp.supermicro.nl/utility/IPMICFG/):
Command:
1. Run IPMICFG –SDR to get list of sensors and the sensor #
2. Run IPMICFG.exe –SDR del 1  (to disable sensor #1 for example)

IPMI FAN thresholds:
https://forums.servethehome.com/index.php?resources/supermicro-x9-x10-x11-fan-speed-control.20/
https://www.truenas.com/community/resources/how-to-change-ipmi-sensor-thresholds-using-ipmitool.35/

Linux:
$ sudo ipmitool sensor thresh FAN1 lower 200 300 400
Locating sensor record 'FAN1'...
Setting sensor "FAN1" Lower Non-Recoverable threshold to 200.000
Setting sensor "FAN1" Lower Critical threshold to 300.000
Setting sensor "FAN1" Lower Non-Critical threshold to 400.000
$ sudo ipmitool sensor thresh FAN5 lower 200 300 400
Locating sensor record 'FAN5'...
Setting sensor "FAN5" Lower Non-Recoverable threshold to 200.000
Setting sensor "FAN5" Lower Critical threshold to 300.000
Setting sensor "FAN5" Lower Non-Critical threshold to 400.000

Windows:
Find IPMIUtil on http://ipmiutil.sourceforge.net/

You should be able to use the below commands (this was specifically for an X12SCZ)

ipmiutil sensor -n 41 -u 400:300:200:35420:35560:35700
ipmiutil sensor -n 42 -u 400:300:200:35420:35560:35700
ipmiutil sensor -n 43 -u 400:300:200:35420:35560:35700
ipmiutil sensor -n 44 -u 400:300:200:35420:35560:35700
ipmiutil sensor -n 45 -u 400:300:200:35420:35560:35700
ipmiutil sensor -n 46 -u 400:300:200:35420:35560:35700

 

 

I don't want to disable these FANs as I want to remote-monitor them in case of failure or some other problem.

 

What I already tried was:
- Setting the LCT to 280 RPM and (just to test) to 140 RPM --> BMC still shows critical and ignores the value
- Reset BMC (Reboot)
- Reset BMC to factory defaults
- FAN-Control using the IPMI-Plugin

 

Another thing I noticed is that if I try to set the LCT using the ipmi-sensors-config (FreeIPMI using the IPMI plugin) it throws errors for most of the values saying the value is not allowed. But for some values it does work, e.g. 140 RPM. If I set the LCT via IPMI-Plugin Unraid WebUI using the "sensor config" I can set any value I want and its also shown in the WebUI. Therefore I tried setting the LCT values to 140 RPM (see image), and its seems to be recognized by the BMC but it just ignores it. And anayways the IPMI plugin sets the Fan Configuration to "Full Speed" which makes the LCT values irrelevant in that configuration.

 

On 5/19/2025 at 3:51 AM, CyberDev said:

Thanks for the reply!

 

Is resetting with IPMITool the same as resetting to factory defaults via BMC/IPMI WebUI? If so, than I already did this several times, unfortunately without success.

Afaik the LCT for the Noctuas are 280 RPM - this is at least the value to which the fans briefly jump by themselves.
By default the LCT is set to 420 RPM with a hysteresis of 140 RPM in both directions. I don't know if there is a correlation between the LCT and hysteresis as 420 RPM - 140 RPM = 280 RPM. But this could also be just a coincidence.

In the meantime I got an answer from the Supermicro Support:

 

I don't want to disable these FANs as I want to remote-monitor them in case of failure or some other problem.

 

What I already tried was:
- Setting the LCT to 280 RPM and (just to test) to 140 RPM --> BMC still shows critical and ignores the value
- Reset BMC (Reboot)
- Reset BMC to factory defaults
- FAN-Control using the IPMI-Plugin

 

Another thing I noticed is that if I try to set the LCT using the ipmi-sensors-config (FreeIPMI using the IPMI plugin) it throws errors for most of the values saying the value is not allowed. But for some values it does work, e.g. 140 RPM. If I set the LCT via IPMI-Plugin Unraid WebUI using the "sensor config" I can set any value I want and its also shown in the WebUI. Therefore I tried setting the LCT values to 140 RPM (see image), and its seems to be recognized by the BMC but it just ignores it. And anayways the IPMI plugin sets the Fan Configuration to "Full Speed" which makes the LCT values irrelevant in that configuration.

 

Which BMC version are you on? SM has begun restricting fan control from 3rd party control.

I'm having the issue getting my fans to slow down since replacing my old front fan wall Arctic F12 PWM fans that went out. I adjusted the numbers to match the fans but can't get them to slow in any mode now after adjusting them. Currently set to "Optimal" in SM BMC. I've done the unit reset as well and they spin back up to full (or over) when the BMC full settles. Any suggestions? Does the BMC need downgraded?

Supermicro X10SL7-F

Front Wall Case Fans (Headers 1-3): Arctic P12 PST CO (400-3000)

Exhaust Wall Case Fan (Header 4): 2x Arctic F8 PWM (300-2000)

CPU Fan (Header A): Arctic Freezer 12 CO (300-2000)

Edited December 25, 2025Dec 25 by SteelsFinest
Added MB Model.

1 hour ago, SteelsFinest said:

I'm having the issue getting my fans to slow down since replacing my old front fan wall Arctic F12 PWM fans that went out. I adjusted the numbers to match the fans but can't get them to slow in any mode now after adjusting them. Currently set to "Optimal" in SM BMC. I've done the unit reset as well and they spin back up to full (or over) when the BMC full settles. Any suggestions? Does the BMC need downgraded?

Supermicro X10SL7-F

Front Wall Case Fans (Headers 1-3): Arctic P12 PST CO (400-3000)

Exhaust Wall Case Fan (Header 4): 2x Arctic F8 PWM (300-2000)

CPU Fan (Header A): Arctic Freezer 12 CO (300-2000)

Hi,

first of all - I'm really sorry for not responding @DiscoverIt.

I just forgot to answer your question because suddenly everything was working properly in my system.

Maybe this will help you @SteelsFinest:

What I did was installing the IPMI-Tools Plugin from the App-Store. After that I did a reset of the BMC and afterwards I configured the IPMI according to my preferences.

E.g. the devices for polling temperatures and global sensors. Additionally I configured the "Fan Control"-Tab which is responsible for the FAN-Speeds.

Somehow what I wasn't able to do manually was properly done by the IPMI-Tools plugin.

After the polling time of e.g. 3 minutes, the fan speeds got adjusted and finally the speeds decreased.

One important thing though: After IPMI-Tools plugin takes control of the fan speeds - do not manually override the fan speeds behavior using the BMC as this breaks the configuration of the IPMI-Tools plugin somehow. At least in my case.

I hope this will help you in any way - unfortunately it was nothing more than trial and error for me - until its got working.

13 hours ago, CyberDev said:

Hi,

first of all - I'm really sorry for not responding @DiscoverIt.

I just forgot to answer your question because suddenly everything was working properly in my system.

Maybe this will help you @SteelsFinest:

What I did was installing the IPMI-Tools Plugin from the App-Store. After that I did a reset of the BMC and afterwards I configured the IPMI according to my preferences.

E.g. the devices for polling temperatures and global sensors. Additionally I configured the "Fan Control"-Tab which is responsible for the FAN-Speeds.

Somehow what I wasn't able to do manually was properly done by the IPMI-Tools plugin.

After the polling time of e.g. 3 minutes, the fan speeds got adjusted and finally the speeds decreased.

One important thing though: After IPMI-Tools plugin takes control of the fan speeds - do not manually override the fan speeds behavior using the BMC as this breaks the configuration of the IPMI-Tools plugin somehow. At least in my case.

I hope this will help you in any way - unfortunately it was nothing more than trial and error for me - until its got working.

Thank you for your reply. The PMI Tools is what I'm using. I guess I'll try tweaking options more to see if anything changes.