SinLoon PC 8 Channels Fan Hub Knob Cooling Fan Speed Controller for CPU Case HDD VGA PWM Fan PCI Bracket 12V Fan Control- SATA Interface Power Supply (SATA 1Knob)

rmp in bios... its probably ramping your case fans based on CPU temperature? most fans at 20% will be silent so they are definitely not staying at that RPM You could swap to manual fan controller: https://www.amazon.com/SinLoon-Channels-Controller-Control-Interface/dp/B09DGB1WY3 Run all the case fans into this and just dial it down to your liking. Or, swap to corsair link fans with an AIO and be able to do things like this: Variable pump speed, GPU responding case fans, AIO tracking water Bundles are great for this: https://www.corsair.com/us/en/p/bundles/titan360lcd-lx120r3pack/icue-link-titan-360-rgb-lcd-cpu-cooler-and-lx120-reverse-triple-fan-bundle?position=24&queryID=a6548ec7bde1b6a66d23b056f6fe7a00