I have a very good Case, so the CPU-Temp is about 25° when idle and the minimum Fan Speed 20% PWM is about 667RPM . That is why I would like to setup my CPU-Fan to stop, in case the cpu is below 35°. On former Mainboards, which that did not require PWM, it was possible - now minimum Speed ist 20% it god damn creats dust in the room, when the fan is running without need. How can I configure the fan to run only under system load?

@jan771 - Posting a link to your BIOS would be a good way to have someone check to see if they could help

You can download it. It is a ASUS H170m Plus:
https://dlcdnets.asus.com/pub/ASUS/mb/LG...S-ASUS-3805.zip

Thanks @jan771 - I can change I think, at least was able to and have it reflected in AMIBCP.
But to flash Asus mod BIOS you have to flash a certain way, and I assume your model does not have USB Flashback correct? I don't see in the specs.
Please download Intel ME System Tools V11 from this page in section "C" and install ME drivers from Asus page if you have not already
Intel Management Engine: Drivers, Firmware & System Tools

Inside you will find Flash Programming Tool folder, and inside that a windows or Win32 folder, select that and hold shift then press right click, choose open command window here (Not power shell)
Then type the following command, and zip and upload the created file for me to edit.

FPTw.exe -bios -d biosreg.bin

In order to flash back mod BIOS when I sent back you will need to unlock "BIOS Lock" here is my guide on that, you can start at step #6 because here's your variable >> 0x8A7
Your .efi file needs to be named >> Shell.efi
[GUIDE] Grub Fix Intel FPT Error 368 - BIOS Lock Asus/Other Mod BIOS Flash

it is no problem. I have a Flash Writer and can flash the Bios at will. But is there a configuration I can alter?
It is such a joke, that I can configure 200RPM to 600RPM in the Bios as minimum, but the Speed will be always 660RPM.

@jan7711 - OK, send me dump from your programmer then, I will modify that instead of stock, that way you don't have to worry about loosing serial, UUID, etc.
That 200RPM setting is a "Warning" setting, not meant to adjust fan speed

"CPU Fan Speed Lower Limit - Select the lower speed limit for the CPU fan. A warning message will appear when the limit is reached. [Ignore]: No future warning message will appear."

To set minimum fan speed you have to adjust "CPU Fan Min. Duty Cycle (%) - Configure the CPU lower temperature to make the CPU fan operate at the min. duty cycle when the CPU temperature is lower than the limit.
The CPU fan will operate at the min. duty cycle when the CPU temperature is lower than the CPU lower temperature."

That is locked at 20% in stock BIOS as you mentioned already finding out, this is what I will set to 10% and then you test to see if 1. it works/bootable, and 2. it actually lowers fan speed to 10% or less than current minimum.
If it is working, then I will set to zero for you in a second mod.

Noone has an idea? It should not be that difficult, q-Fan-tuning just allows minimum of 20% of the RPM. How can I set it to 0%?

@jan771 - I am trying to help you, waiting on dumped BIOS to modify, you can dump via FPT as outlined above, or using your programmer. And then yes, I believe I can change this for you, have already done and confirmed the changes reflect on my end, but you need to test, so send me your dumped BIOS.
I am editing CPU Fan Min. Duty Cycle (%) from 20% to 10% as test, then will do zero% once you confirm 10% works as expected.

Can you describe how can I change the Duty Cycle on my own?

@jan771 Yes, sorry I assumed maybe you didn't want to dig in there yourself, if you know about modifying BIOS files I can tell you.

Extract AMITSE >> SetupData Module from the main volume image, then edit via hex @ 0x55519h, change 14h (20 dec/20%) to 0Ah (10 dec/10%), or for zero% and I do still suggest you test 10% first, set 00h instead of 14h.
Then put back into AMITSE >> SetupData and rebuild the image. If done correctly, you will see your changes reflected in AMIBCP at CPU Fan Min. Duty Cycle (%) to a new 10 or zero instead of 20
Then flash the mod BIOS, if you plan to use programmer then dump your BIOS and do this edit, don't program a stock edited BIOS or you will loose your system details (serial, UUID, LAN MAC ID etc)

@jan771 - for my reference, can you confirm these changes work or not, does it apply 10% or 0% when you set your desired 0%?

Why is there no FTK for 11 ME Firmware? I am not familiar with AMITSE

@jan771 - FTK is a "User put together" type package. FTK itself has many Intel ME tools, I thought for all ME versions up to 12 too, maybe you have old version FTK package?
I checked my storage and I see FTK 12 only has ME Tools up to V10, so as I mentioned not up to date.

Here is where you download ME System Tools package for V11 ME, in section C, these will all be updated latest versions, FTK packages are not updated frequently like this thread below is
Intel Management Engine: Drivers, Firmware & System Tools

Being familiar or not with AMITSE doesn't matter if you know how to modify BIOS, I gave you method to do it via hex. This is why I asked you to send me your BIOS dump, so I could modify it for you
I still suggest you do this, unless you have flash programmer and can easily recovery from a bad BIOS flash.

ok, setting the SetupData position to 0x55519h to zero did not work. It changed nothing at all. But the UEFI Tool did replace a lot more than this edited Byte in the Bios file.

I thus would not recommend using this UEFI-Tool at all.

@jan771 - that can only mean you are doing the mod wrong, if you are seeing "Replace a lot more than this edited byte" How are you checking that?? It only puts in what you give it, re-extract and check, it will match exactly what you inserted, if not then you're doing something wrong.

UEFITool is 100% great awesome tool everyone uses it all day long all around the world for many different uses and modifications, you just don't understand what you are doing or how to use etc (No offense meant, we all have to learn)
But, this is why I asked you 10 times now to send me your backup BIOS region and I will do the mod for you. Luckily you have not bricked your board yet!

I also suggested to set 10 first and see if that worked or not, you can't just set "10" >> change 14h (20 dec/20%) to 0Ah (10 dec/10%)