Cant run more than 14 asic saphires on cgminer! They all run off MB so power is not an issue. Runs fine with 14 but if I plug in one more cgminer stops working! Any1 else had this problem? 
You've got 14+ USB ports on your Mother Board? Even if you truly did I doubt that it would supply 7 AMP's to the USB Ports, unless it is USB 3.0.
What Operating System are you using? Windoze XP limited me around 12 or 13 devices. Where WinVista goes up to 50 and Win7 goes up to 60.