Because each miner has its own power supply
Im wondering can i just run a basic 10 port USB hub, and attach my miners to that, then the hub to the PI
Or is there a limit how many U3 you can actually run
Did you get managed to set up your miners?
I'm running 4x U3 on an Raspberry Pi2 over WLAN. All of them work like a charm.
Send me a pm, if you would like to know the start settings (freq and voltage) I use.