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[BIOS 0054] Why does the Custom fan control mode have a locked minimum speed of 27%?

Bios Version: QXCFL579.0054.2020.0810.2239
Processor: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
Intel® NUC 9 Extreme Compute Element - NUC9i7QNB
All symptoms are visible in the bios environment (and are consistent in Win 10).
Bios settings are otherwise defaults.

Sorry this is long (or if already reported), TLDR at the bottom. Any insight or news of a potential fix would be greatly appreciated.
Note: My OEM CPU fan is otherwise balanced and undamaged, but mounted in a flimsy shell (the NUC), and the PC case is not soundproof.

For this machine to live in the same room as me, a CPU fan speed of 13% in the Fixed profile is quiet enough. At 13% the CPU rarely gets above 50C while doing most things. An extended benchmark will level-out at ~90C, which of course is not ideal, but ok.
Having said that, I had to disable Turbo (down to 2.6 GHz) to make this possible.

So 13% fixed speed is good at keeping things cool, and certainly better than 0%. 0% being the min speed of all other profiles (Cool, Balanced, Quiet).
Ideally, what I need to continue using this NUC (and when considering purchasing the next iteration) is to reactivate Turbo and have the min speed set at 13% instead of 0%, so the fan stops rushing to get under the off-threshold as soon as it crosses it... then turning itself back off, constantly repeating that cycle.
I was convinced the available Custom settings would allow me this, but it just doesn't get slow enough.

The crux of the problem is: unlike with Fixed, the Custom profile has the benefit of the fan ramping-up and stopping the Turbo 4.5 GHz melting everything, but no matter my settings, the fan will not drop below ~1410 RPM even when everything is nice and cool.
(for Fixed, my Duty Cycle is set at 13% ~654 RPM.)

I thought these settings.. :
Fan Off Temperature (C) - 50 (the default)
Minimum Temperature (C) - 72 (the default)
Minimum Duty Cycle (%) - 13 (default is 27)
Duty Cycle Increment (%/C) - 2 (the default)
... would have the CPU fan spinning at ~654 RPM (13%), and then ramping-up after crossing 50C.
Instead what happens is...
the fan spins at ~1410 RPM above and below 50C. Even a Minimum Duty Cycle of 0%(off) spins at ~1410 RPM.

... upon further testing I realised the Minimum Duty Cycle (%) is only for when the CPU temp is above the Fan Off Temperature. Even then, 13% (~654 RPM) is not respected, and the fan continues to spin at ~1410 RPM (27%).
So... I guess 1410 RPM is "off", for any temp below the Fan Off Temperature ¯\_(ツ)_/¯ and unlike the 3 named profiles, there is no chance of the fan ever turning off.

With Custom control mode I would like the same freedom as I have with Fixed (where I can set the Duty Cycle as low as 0%), and for this minimum fan speed (~1410 RPM) to be removed, so at least others can have their CPU fan turn off below the custom threshold, if that's what they want.

Thank you!
I hope I can live my quiet, Turbo powered dreams in the future.
(Some images attached for reference)


With the Custom cooling fan mode:

- At temperatures Below any set Fan Off Temperature, the fan constantly spins at ~1410 RPM (unlike the other profiles Cool, Balanced, Quiet & Fixed which will go to 0 RPM).

- At temperatures Above any set Fan Off Temperature (but still below Minimum Temperature), the fan also spins at ~1410 RPM if the Minimum Duty Cycle is set to anything lower than 27%.
(in contrast the Fixed control mode allows anything from 0-100%)

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14 Replies

Hello Crumb,

Thank you for posting on the Intel® communities.

To better assist you please provide the following report and information to continue with your support request.

-Please run the following tool and attach the report generated.  

Intel® System Support Utility (Intel® SSU)

Download link:


•          Open the application and click on "Scan" to see the system and device information

•          By default, Intel® SSU will take you to the "Summary View".  

•          Click on the menu where it says "Summary" to change to "Detailed View".  

•          To save your scan, click on "Next", then "Save".

* Use the option under the reply window to attach the report to the thread (Drag and drop here or browse files to attach).

-Could you please confirm if what you are looking forward to achieving is to have the turbo feature enabled in BIOS along with a custom fan profile (13%) and maintain the fan’s RPM at 654 RPM independently of the CPU’s load?

I look forward to hearing from you.


Victor G.

Intel Technical Support Technician  


Hi Victor. Thanks for getting back to me.

Let's forget about the Turbo feature for now.

I've been using the Fixed profile at 13%, but I would like to use the Custom profile, so the fan can respond when the CPU temp increases. (I want a Minimum Temperature target.)

I have attached 3 images (status of CPU fan after saving and rebooting):

(a) Default Quiet profile. CPU fan = 0 RPM. As the CPU temperature is currently below the threshold.

(b) Clone of Quiet. CPU fan =  1413 RPM. Fan should be Off at this point as it is below the threshold.

(c) My ideal settings. CPU fan = 1413 RPM. Fan should be On at 654 RPM (until reaching the Min Temp).


(i spliced each pair of photos together to make things easier) 


Hello Crumb,

Thank you for posting on the Intel® communities.

We appreciate the information provided, we will use it to do further research about it on our end and we will update this thread as soon as possible.


Victor G.

Intel Technical Support Technician  


Hi Crumb,

I have been playing with the settings that you want to achieve but I couldn't way to get there, at least not if using the Intel Chassis (are you using a 3rd party chassis?) and in a regular environment of around 23C. I dont know what would happen if the ambient temperature goes as low as Data Center environment -17 or 18C so that CPU and PCH temp reports less than 50C but with my readings, the Fan Speed reports about the same 1490 RPMs.

I would say this is the expected behavior of the system BIOS in order to protect the system from overheating.



Ronny G


Hi, thanks for your reply.
Yes my space is 23C. 
I'm using the third party chassis from Cooler Master (MASTERCASE NC100).
(There is no GPU installed in the other slot, just the NUC.)

I'm currently running with the Fixed profile at 13%, and the CPU fan is at 650 RPM.
I want to protect myself from overheating, that's why I want to use the Custom profile.

What is silly IMO is that Cool, Balanced & Quiet let the CPU fan go to 0 RPM.
I want to make the base speed 650 RPM (13%) to stop the fan from needlessly stopping and starting all day.

Can you see if the CPU fan sets itself to 0 RPM when using Cool, Balanced or Quiet?

If so, then it seems there is a bug with Custom profile as it's behaviour is not consistent, and it ignores the Fan of Temperature. It is also not consistent with the custom setting in the Fixed profile, which allows a Minimum Duty Cycle of 13%.


1. Please use the cooling profile: Cool, Balanced or Quiet.
2. Save & restart.
3. Check the fan speed in the BIOS. Is it 0 RPM?

Super User

@Crumb   You are responding to a spammer.  I have already reported that post as spam.

Doc (not an Intel employee or contractor)


Hi Crumb,


Yes, I have witnessed the FAN RPMs = 0 but only for a second until it refreshes and then I get a regular RPM value.

I was also able to set the system as you mentioned, see below:


Refer to the following website for further information:


Ronny G


Thank you for the link, but the settings and parameters detailed on that page do not reflect those of my NUC9i7QNB (and the current BIOS). 
"Fixed: Allows the fan speed to be set at a fixed speed and never change. Options are from 20 to 100 percent in 10 percent increments."
However, my (and your) experience for Fixed is- Options are from 0 to 100 percent in 1 percent increments.
Also, there is no mention of the Fan Off feature present in the pre-set and Custom modes.  

It may be time for that page to be updated. 


I appreciate you peeps trying to replicate my issue.

As you have seen:
any Fixed fan speed can be set, so there is no BIOS failsafe speed.

Please enable this level of control for the Min Duty value in the Custom profile. Thank you.

I don't want to listen to the maddening rhythm of the pre-set profiles that turn my fan On and Off... silly behaviour for a fan.
I don't want to listen to a fan stuck at 27%.
These are my choices atm. 

Please, I need your help if I want to move away from the Fixed profile and actually use this machine.
(I'm happy to test any beta versions of this BIOS when they become available.)

Super User Retired Employee

FYI - I tried this on my QNX unit and I am seeing the same issues.



Hi Crumb,


As also mentioned mentioned by  I was able to replicate the same behavior.

Allow me a couple of days to check with the Product Team and I will get back to you.



Ronny G


Hi Crumb,


This is just to let you know that after replicating this issue I created an internal ticket to investigate this issue and we are currently investigating. 

Please keep in mind that this may take some time.



Ronny G 


Thanks guys!