My ASUS Sabertooth 990 fx R2.o Gen 2 mobo has 6-4 pin fan connectors, Asus tech support said that the 2 C.P.U. Connectors were Pulse width Modulation fans. but are the case fans also controlled by the mobo, Adjusting fan speed Automatically and does that mean off to on, Or variable speed as needed. I can not get that answer out of them. I know that a PWM fan (Pulse Width modulation) fan voltage is controlled by turning the voltage off and on at a rate that equals lowering the voltage without the use of resistors saving power and causing less heat for the mobo to dissipate. This is my first build and I do not understand the terminology, And as I am learning that is quite a undertaking into its self. All 6 fan headers are 4 pin connectors.