I'm sure this question has come up but I've spent about 2 hours looking for a real answer and haven't found one. I'm currently running 12 fans on 2x360 radiators and each rad (6 fans) has it's own hub with sata power adapter. Currently I'm using a single cable (2 wires) to supply 1 tach signal and retrieve 1 PWM signal from the mobo for all 12 fans. My question is, how much is too much? I would assume eventually the PWM signal has to degrade enough to be detrimental. Does anyone know the answer?