CHA2 fan N/A in BIOS

[frob]

Hi all,

I've recently changed a case and I'm having a slight problem. CHA2 fan in BIOS shows up as N/A while CPUFAN and CHA1FAN are normal.

My case (Fractal Design R6) comes with a fan hub and the manual says to connect one of the pins to the CPU_FAN header and the power to the PSU, which I done. My fans came with the case (Fractal Design Dynamic X2 GP-14). The rear fan is connect to CHA1 header and can be read from the BIOS. The front intake fans are connected to the fan hub and are not detected.

Am I doing something wrong or is this normal? Is there a way for me to read the RPMs of the front intake fans? My motherboard (ASUS H97M-PLUS) only has 2 chassis fan headers.

 

[Paperdoc]

Any fan header can read the speed signal coming back to it of only ONE fan. If you were to connect the speed signals from more than one fan to a header, it would become very confused with superimposed chains of pulse signals and generate wildly fluctuating (and wrong!) speed readings. So, and decent fan Hub or Splitter will return to the host header only ONE fan's speed signal, and ignore all the others it has. Your Hub serves the CPU cooler which REALLY should be plugged into the particular port on the Hub specified for that, because that is the ONLY fan's speed reported by the Hub to your mobo CPU_FAN header. That header NEEDS to see the speed of the real CPU cooling fan. The Hub also powers and controls the speed of the two case ventilation front intake fans, but it cannot report their speeds to the mobo anywhere, so you will never "see" their speeds. You do have one fan plugged into a mobo CHA_FAN header, and its speed is being reported properly.