Thank you. was actually testing it with prime95 under full load on setting 3. When I turned it down to setting 1 (lowest), i can gradually hear it go down slowly to almost silent. Then vice versa.
The only thing i dont understand is that when i look at my mobo its showing that the fans (connected to the water block) are running at 2200RPM by default. I tried changing it in the bios setting, and it wouldnt slow down.
Your motherboard isn't controlling anything about your CPU fan. That option you see in the BIOS is assuming you have a 3pin fan header connected directly from the heatsink to the motherboard. Think: stock intel fan.
You're using a 4pin Molex directly off of your power supply to provide current to the h100, which handles all fan duties itself.