Arctic f12 pro pwm 120mm case fan perfect case fan regulation with pwm the pwm function allows the motherboard to run the fan precisely at its necessary speed this guarantees the required cooling and minimizes the noise level patented pwm sharing technology pst lowers noise if you want to improve the cooling efficiency of your computer you get several case fans working in parallel since it takes 10 fans to double the noise level but what does it help if they dont work together the pst