the hub i'm using in that picture is the much discussed 12 port usb hub from saitechi. it wouldn't power more then 3 erupters. i've got an anker 10 port usb 3.0 now (and two more en route) running five of them plus the fan and my cell phone charger no problem.
anyone know a readily available USB hub which support individual port port power 'on' and 'off' using software such as usb-ctrl.c? I have seen mentions of these but yet to find an easily available model. I guess it would be ideal for Block Erupter USB.
http://askubuntu.com/questions/149242/is-it-possible-to-power-up-ports-on-a-usb-hub-from-ubuntu