randomkid

Distinguished
Or set into SmartFan with the target temperature too close to your idle temperature. When your CPU exceeds the range of your target temperature, it will speed the fan up and once it cools down, it will slow down again... then the cycle repeats.

Try to check your SmartFan setting and set the target temperature higher if you want your fan to be consistently slow or set the target temperature lower if you want your fan to be consistently fast.