As mentioned, use custom and do not try to "Set below 60" Apply custom, reboot and test fan RPM or measure voltage vs stock. I did not change anything yet that will allow you to set lower manually yet, I've only changed behind the scenes applied defaults.

@agentx007 Wii I be able to change fan speed after that modification ?

Yes, BUT since instead of 12V you will get 7V max. - I don't why you would want to...
Also, some fans can't even start at lower than 7V (so setting less than 100% at the start, may be bad idea).

@agentx007 It seems very difficult to make your modification. You say "Can't you simply connect" but for me is very difficult ! Should I put the black wire out from the fan connector and connect it on a molex ? I have many fans and the cable management will be very weird in my case ! I can't really imagine your technique. Can you make a picture or something else ?
I don't really want to make hardware change to my fan or whatever. I thought that we can only make change to the software level or BIOS level. I preferred the "Speedfan" technique compared to put the black wire out or in worst scenario, buy another motherboard & better fan !
But good to know that we can do like this too !

Please note that I'm in "PWM output" in speedfan & not in "DC output". (So control fan speed with PWM and not with DC)
PS : I don't really know if it has a relationship, but I put this information.

@Lost_N_BIOS I tried too to put only custom without any modification (leave it by default). I (think) don't really need to test voltage because I'm under PWM output (I don't really know to be honest). And I only need to hear if the fan speed go lower.

I think you miss the point of PWM :D
PWM doesn't mean it's AC power.
It simply provides fraction of maximum voltage to power the motor (by switching On/Off really fast).
Max. voltage is determined by difference between "+" and "-" (yellow and black wires usually).
Since you get 12V on "+" and 0V on "-", you can get maximum fan speed range for 12V fans.
In my case, instead of "0V" we use "+5V". This means you effectively have 7V as maximum voltage (12V - 5V = 7V).

Sorry if it seems complicated.
I tried my best to make it simple...
Here's two step way of doing this :

Step 1 : Detach black wire from fan connector


Step 2 : Sqeeze it into Molex 5V pin :

Done.

PS. Don't worry. It works on 4-pin connectors as well (you simply need to find "-" or "ground" wire) ;)

There is also adapters made for this, here's a few examples
https://www.amazon.com/Silent-3-Speed-Ca...V/dp/B000XQOQSS
https://www.amazon.com/dp/B00EURESG6/ref..._detail_3?psc=1
https://www.amazon.com/dp/B004CLJ892/ref..._detail_0?psc=1
https://www.amazon.com/dp/B002PNFEM4/ref...4_t2_B000XQOQSS

I'm not certain, but maybe the changes I've been making could be working, but only affect DC voltage mode, not PWM? Can you test BIOS I made (first ones, and latest) vs stock, with a voltage 3 pin fan?

THANK'S TO ALL OF YOU FOR HELPING TO UNDERSTAND MORE ON MY FAN ! I REALLY APPRECIATE THIS COMMUNITY !

@elisw Thank you for giving more information about my hardware !
@Lost_N_BIOS Thank you for your hardwork to help to make modded BIOS & help someone unknown in this vast world !
@agentx007 Thank you for your new technique, I never heard that before, I will test this soon !

I will consider all of your reply !
I think it wil be my last "Reply" on this topic !

PS : @Lost_N_BIOS Last question, do I have to re-flashing my latest stock BIOS to recover "Serial number" or whatever modded subsystem ?

@Manaien10 - your serial, UUID etc should all be same as they was, since I only used your dump for all modification BIOS, so all that remained in place.
however, if you want to go back to stock BIOS, without the modifications, reflash your first FPT backup BIOS region via >> FPTw.exe -bios -f biosreg.bin
Do not flash stock BIOS that way, only your original FPT BIOS region dump you created and posted in post #12

So.... For me, still unclear if any of this worked or not, at least not with any real certainty I have Asus Z170 boards here though, so I can find out if these methods work for sure or not on my end via DMM
@elisw will do when I have time!

Hello Sir.

I have same situation with my asus b85m-e. Min fan speed at 60%
All pins is PWM. I try to reduce fan speed from 1115 to 800 rpm.
With ai suite under windows i can change with 5rpm steps (600 - 2200 rpm), but when PC starts - coolers works at full speed, too noisy :)
Can you pls help me to modify bios?
I have more experience than a topstarter.
Just tell me what areas of the BIOS are u correcting, and what kind of software u use :)

Will log any steps here with results.

@ctacb - Check BIOS main page and see if ME FW version is shown, if not then download HWINFO64 and on the large window on left side, expand motherboard and find ME area, inside that get the ME Firmware version.
Once you have that, go to this thread and in the section "C" download the matching ME System Tools Package (ie if ME FW version = 10.x get V10 package, if 9.0-9.1 get V9.1 package, if 9.5 or above get V9.5 package etc)
Intel Management Engine: Drivers, Firmware & System Tools

Once downloaded, inside you will find Flash Programming Tool folder, and inside that a Windows or Win/Win32 folder. Select that Win folder, hold shift and press right click, choose open command window here (Not power shell).
At the command prompt type the following command and send me the created file to modify >> FPTw.exe -bios -d biosreg.bin

Right after you do that, try to write back the BIOS Region dump and see if you get any error, if you do show me image of the command entered and the error give >> FPTw.exe -bios -f biosreg.bin

If you are stuck on Win10 and cannot easily get command prompt, and method I mentioned above does not work for you, here is some links that should help
Or, copy all contents from the Flash Programming Tool \ DOS folder to the root of a USB Bootable disk and do the dump from DOS (FPT.exe -bios -d biosreg.bin)
https://www.windowscentral.com/how-add-c...creators-update
https://www.windowscentral.com/add-open-...menu-windows-10
https://www.laptopmag.com/articles/open-...ator-privileges

@Lost_N_BIOS thx for Answer!
I have time today, and going to try all you said :)

@Lost_N_BIOS

I'm on win7
Bios ver. 3602.
ME VER 9.0, build 1333 hot fix 1 :)
Asus download page - https://dlcdnets.asus.com/pub/ASUS/mb/LG...E-ASUS-3602.zip

FPTw.exe -bios -d biosreg.bin
Intel (R) Flash Programming Tool. Version:  9.1.10.1000
Copyright (c) 2007 - 2014, Intel Corporation. All rights reserved.
 
Platform: Intel(R) B85 Express Chipset
Reading HSFSTS register... Flash Descriptor: Valid
 
    --- Flash Devices Found ---
    W25Q128BV    ID:0xEF4018    Size: 16384KB (131072Kb)
 

- Reading Flash [0x1000000] 11264KB of 11264KB - 100% complete.
Writing flash contents to file "biosreg.bin"...
 
Memory Dump Complete
FPT Operation Passed
 

FPTw.exe -bios -f biosreg.bin
Error 280: Failed to disable write protection for the BIOS space!
 

ok, i try to use
AMI IFR Extractor [Tool Guide] AMI Setup - IFR Extractor AMISetupWriter
or Using the AMI tool AFU t455f16-Guide-How-to-flash-a-modded-AMI-UEFI-BIOS.htm
Amm..
I tryed AFU, and seems to be it's done with original .CAP bios.
But i have no modifed bios (.ROM file) to try WRITE bios to flash with AFU.

Hmm.
Some guy writed about method with originals_modded bioses.
[Guide] How to flash a modded AMI UEFI BIOS (17)
Do you have some method to mod originals bioses? :)

Sleep mode is on :)

@ctacb - You might be able to use mod BIOS in EZ Flash, but we'll have to test, low chance it will work. Other methods like the AI Suite method works sometimes too
Or you can try this method, download files in this guide, then pay attention only to last spoiler for flash method (Mainly this is flash stock BIOS first, then mod BIOS without a reboot, using the AFU in that guide)
https://linustechtips.com/main/topic/592...r-motherboards/
Similar/same method described here - [Guide] How to get full NVMe support for all Systems with an AMI UEFI BIOS (132)

Send me your biosreg.bin file and I will make simple edit so we can test and figure out working flash method before we try the actual fan edit changes.

Since you mentioned sleep, please try this. Put system to sleep (S3) for one minute, then wake it up and try the FPT flash again, sometimes this disables the block due to BIOS bug. If that works, then we can flash via FPT

https://cloud.mail.ru/public/3Qv2/3gTzRciut

Thanks, please let me know about the sleep test I mentioned.

Then, before I send you anything modified to test, try this. Follow this guide, you can start at step 6, I've done 1-5 for you and the info is below
[GUIDE] Grub Fix Intel FPT Error 368 - BIOS Lock Asus/Other Mod BIOS Flash

Rename your .efi file to Shellx64.efi

You'll be disabling both of these >>
SMI Lock, VarStoreInfo (VarOffset/VarName): 0x9D
BIOS Lock, VarStoreInfo (VarOffset/VarName): 0x9E

So at grub prompt you will type the following (separately)
setup_var 0x9D 0x0
setup_var 0x9E 0x0

Then reboot to windows and try to FPT flash the stock biosreg.bin file again.
If success, then flashing mod BIOS problem solved and I will work on Fan BIOS for you to test, if problem not solved, then I will send you mod BIOS later tonight to try and flash using the various methods we discussed above.