Thank you very much for responding. Under the Cooling Fans section, Aida64 shows 6 fans for my Minisforum BD770i motherboard:
Chassis 793RPM
Power Supply 1452 RPM
Fan #4 (LM78) 1100 RPM
Fan#5 (LM78) 2616 RPM
GPU1: GPU 0 RPM
GPU1: GPU2 0 RPM
I just don't know which one is the CPU fan.