Supermicro PWM fan help

[lenk]

Hi, I have a Supermicro X11SSM-F motherboard with latest bios and ipmi firmware. I got the dreaded low rpm fan rev. Currently have 3x F12 noctuas (1500rpm) and 2x 80mm noctuas (1800rpm).

In the IPMI/Configuration/Fan Mode Setting the fans are set to Optimal Speed setting. At these setting the fans are revving when it goes into low rpm mode.

So I tried setting the fan threshold lower by:

ipmitool -I lan -H 192.168.0.18 -U ADMIN -P ADMIN sensor thresh FAN4 lower 150 225 250
ipmitool -I lan -H 192.168.0.18 -U ADMIN -P ADMIN sensor thresh FAN3 lower 150 225 250
ipmitool -I lan -H 192.168.0.18 -U ADMIN -P ADMIN sensor thresh FAN2 lower 150 225 250
ipmitool -I lan -H 192.168.0.18 -U ADMIN -P ADMIN sensor thresh FAN1 lower 150 225 250
ipmitool -I lan -H 192.168.0.18 -U ADMIN -P ADMIN sensor thresh FANA lower 150 225 250

But when I do this, the fans just go into full rpm mode. Any ideas what I did wrong here? Thanks

 

[lenk]

I tried rebooting the ipmi unit and also cold reboot the whole system. Still the Fans are revving.

# ipmitool -I lan -H 192.168.0.18 -U ADMIN -P ADMIN sensor list all
FAN1 | 700.000 | RPM | ok | 200.000 | 300.000 | 500.000 | 25300.000 | 25400.000 | 25500.000
FAN2 | 300.000 | RPM | nc | 100.000 | 200.000 | 300.000 | 25300.000 | 25400.000 | 25500.000
FAN3 | 300.000 | RPM | nc | 100.000 | 200.000 | 300.000 | 25300.000 | 25400.000 | 25500.000
FAN4 | 300.000 | RPM | nc | 100.000 | 200.000 | 300.000 | 25300.000 | 25400.000 | 25500.000
FANA | 300.000 | RPM | nc | 100.000 | 200.000 | 300.000 | 25300.000 | 25400.000 | 25500.000

 

[Terry Kennedy]

I tried rebooting the ipmi unit and also cold reboot the whole system. Still the Fans are revving.

This Supermicro FAQ is for the X10, but something similar may be available for the X11. It uses raw commands to set a specific fan speed. I would confirm the specific command(s) for your board with Supermicro before changing things.

 

[lenk]

Thanks Terry, I have no idea how to use this raw commands. Any directions?

 

[MiniKnight]

I'd ditch Noctuas and just let PWM run.

 

[lenk]

MiniKnight: No point having the fans run at full speed, if its not needed.

 

[Terry Kennedy]

Thanks Terry, I have no idea how to use this raw commands. Any directions?

You probably don't want to do that without knowing the specific values for your board. Sending incorrect commands can change other things you don't want to change, or can cause the IPMI to lock up until the power is cycled.

 

[lenk]

Looks like I got it working using ipmiutil from a post on freenas. I guess ipmitool doesn't work on this mobo, or maybe the upper threshold need to be set too at the same time. Check How To: change sensor thresholds with IPMI using ipmiutil | FreeNAS Community

ipmiutil sensor -N 192.168.0.18 -U ADMIN -P ADMIN -n 44 -l 200 -h 2000


Spoke too soon, didn't work.

 

[lenk]

Found the culprit. I got a dud fan. Removed it, and its all working. Funny that the single dud fan causes, all the other fans to rev up.

 

[PigLover]

Found the culprit. I got a dud fan. Removed it, and its all working. Funny that the single dud fan causes, all the other fans to rev up.

That's actually quite typical behavior in enterprise environments - when a fault is discovered the rest of the system "makes safe". In this case the rest of the fans are ramped full in an attempt to cover for missing airflow from the "dud".