My servers fans go full speed for a few minutes then go silent for ~10 seconds. All fans in my system are Noctua fans that support PWM. My motherboard is X9DRi-LN4F+ and the headers support PWM. 

 

I have tried using Dynamix Auto Fan Control and IPMI support plugins but neither have been able to properly adjust my fan speeds. 

 

Throughout my testing with both plugins, my average HDD temps are 21C and my CPU temps are 26C.

 

With Dynamix the fans always ran full speed no matter which sensor I select or PWM controller. 

The IPMI support plugin seems the result in the behavior I stated initially in this post. 

 

I have tried finding a solution for this but it looks like every one has a slightly different issue leading to different solutions.

Can anyone point me in the right direction? 

11 minutes ago, Chandler said:

My servers fans go full speed for a few minutes then go silent for ~10 seconds.

This happens when fans are spinning lower than the the lower threshold settings, you can adjust that with the ipmi plugin.

1 minute ago, johnnie.black said:

This happens when fans are spinning lower than the the lower threshold settings, you can adjust that with the ipmi plugin.

By lower threshold do you mean the fan speed minimum? If so, my minimum is set to the lowest possible (0.3) and the low temperature threshold is also set to 20C which is still lower than the system temps. 

3 minutes ago, Chandler said:

By lower threshold do you mean the fan speed minimum?

No, the BMC setting, accessible on the sensors page, lower non-recover, lower critical must be a little lower than the fans minimum speed:

 

Edited December 30, 20187 yr by johnnie.black

31 minutes ago, johnnie.black said:

No, the BMC setting, accessible on the sensors page, lower non-recover must be a little lower than the fans minimum speed:

Ah I see now in the event log all my fans hitting lower non-recoverable and lower critical errors. I changed the lower non-recover to be 440 as my fans have a minimum of 450. What I don't understand is that I changed the value to be 440 and saved the value at 440 but they seem to be stuck at 450 for the lower non-recoverable. 

 

Before I went to change any of it they were originally set to 300. And now what seems weird to me is that the event log is saying the sensor reading = (High RPM)RPM and that the threshold is 450RPM yet it is triggering the lower critical and lower non-recoverable alarms. 

 

I also get errors saying a value cannot be encoded properly when attempting to save certain values to the thresholds such as setting 500 as the lower critical. I've tried playing around with the thresholds in an attempt to get them to change off of 450 but nothing seems to be working. Looking at the plugin thread I do see you have posted something about how they can only change in 150 increments and that seems to be my issue here. With my threshold being set at 450 or 300 should they still just be able to run at their minimum of 450? Or would they be able to not run at all since my temps are in the 20's C which is fine for me and the fans do not need to be at full speed. 

 

 Do you know where I need to go from here? 

 

 

Depending on the board you can only use some values, some use 150, 300, 450, etc, others use 100, 200, 300, 400, etc.

3 minutes ago, johnnie.black said:

Depending on the board you can only use some values, some use 150, 300, 450, etc, others use 100, 200, 300, 400, etc.

Well mine appears to not be able to use 400. Just 300/450. Does this mean I cannot get my fans to properly adjust their speed for the system temps?

You can, just set the lower thresholds to 150 and 300.

1 minute ago, johnnie.black said:

You can, just set the lower thresholds to 150 and 300.

Alright and should I leave the higher one at 600? 

 

And with these settings does it ever give the fans the opportunity to be at 0 RPM when the system is cool enough or do they just sit at the lowest RPM? 

Fans don't usually go to zero, like mentioned before:

13 hours ago, johnnie.black said:

lower non-recover, lower critical must be a little lower than the fans minimum speed

 

21 hours ago, johnnie.black said:

Fans don't usually go to zero, like mentioned before:

 

So after changing the lower 2 to 150 and 300 the fans still bounce from low to high but seem to stay high for a longer period of time (all of my temps are in the high 10's C and low 20's C).

 

 

These logs confuse me -- they say the sensor reading is 0RPM which trips the lower critical event and that makes sense to me. What doesn't make sense is when it says the sensor reading is in the 2 thousands RPM and the threshold is 150 or 300 RPM yet the event is firing off. 

The higher warnings are likely after the fans speed up, the problem are the 0 rpm readings, i.e. if the fans are actually stopping, set the minimum fan speed on the plugin to an higher value.

1 hour ago, johnnie.black said:

The higher warnings are likely after the fans speed up, the problem are the 0 rpm readings, i.e. if the fans are actually stopping, set the minimum fan speed on the plugin to an higher value.

It looks like that has done the trick. Although I had to lower my values to 0/150/300 from 150/300/600 which I believe is fine. The RPM is not as low as I'd like but it is a huge improvement from running at full speed. 

 

I also did some additional research on 0RPM for IPMI and came across a couple posts on servethehome forums about others with Noctua fans and revving issues. 

 

It's too bad there isn't an optimal way to let the fans simply do their thing and not spin when not required to. Thanks for all your help, I'll post back if I run in to another issue.