Here is a tutorial on how to adjust fan speed
When booting, keep pressing the ESC key until the BIOS interface appears.
Find the smart fan mode by the following steps and set values of what you expect to
Menu: Advanced——>Hardware Monitor——>Smart fan mode
P.s.
PWM (Pulse Width Modulation) is a commonly used method of motor speed control. In fan startup, the PWM setting value determines the fan startup speed. For example,PWM values of 60 and 120 respectively represent different start-up speeds.