Technical specifications: Why does it not say anywhere what power the hard drives need when powered via USB? I currently have 10 external hard drives connected to my MacMini via a USB hub. That went well for a long time. But for some time now, 1-3 (especially one) hard drive(s) keep logging off. I suspect that in the worst case several hard disks start up together from sleep mode, causing the USB operating voltage to collapse. The power supply of my USB hub (7+4 expansion) is probably too weak. I wanted to see how much different external USB hard disks draw....but no information. (not even in the manufacturer's data sheet)