Can't run more than 3 Antminer U1's
4 antminer u1's
windows xp sp2
a cheap 10 slot usb hub
cp210x_VCP installs fine
got wallet set up etc, bfgminer configured with the stock command line
I can get up to 3 antminers going at once, though I often have to fiddle around plugging and unplugging things. Adding a 4th always ends up with the last one not recognized. Also shows up as a problem device in windows device manager
Along the way discovered that my cheap 10 slot usb hub has the nasty design feature that it will feed power from its wall wart back into the powered usb port the hub is plugged into. That crashed the pc real fast when I first plugged it in. Ran it without the wall wart, letting the usb port power it, and learned that this is not a good idea because the usb port, I think, does not put out enough power to properly handle even 3 antminers. You can get them recognized but they won't run real well. Slow and with errors.
Busted open my cheap usb port and cut the power wire coming in from the usb port plug so I can actually power the antminers with the wall wart. 3 antminers now running pretty well. But still can't get 4 going.
I'm guessing this is one of those windows type issues. Something about a failure to allocate resources like com ports or irq lines maybe. Have tried a few things through device manager, deleting unused devices to free up com ports for example. Not sure what else I can do though. the pc has an asrock pennryn 1600SLI-110dB motherboard in it. Maybe I need to use another os