ASUS Fan Duty Cycle problem

[locarno]

Hello
I have a question about Fan Duty Cycle. My MB is Asus H170m-PLUS with I5-6600 with stock Intel cooler. It is possible to change Fan Duty Cycle below 20% ? It depends on BIOS limit or cooler limit. If I will buy another cooler then I will be able to set 0% for example ? Stock cooler is annyoing because I have PC near my ear.

I also have problem, after few BIOS updates, now If I change something in chart, then min. Fan Duty Cycle will change to 24% instead 20%

 

[Isokolon]

20% is usually the minimum speed for a pwm-fan (40% for a 3-pin)

Passive cooling for a CPU like that makes little sense as the fan would start to spin 2 minutes after boot up the latest and wouldn't stop

 

[locarno]

So If I buy another cooler there still be 20% limit ?