Are you using vthoan's cgminer 4.10? I know with the official ckolivas cgminer 4.10, USB device is detected as UMO (?) and gives half the hash rate. 100 Mhz should give you around 10 GH/s on correctly recognized device. Unless the hardware is defective, it could be a the wrong cgminer.

Thanks for the help. I'm rebuiding cgminer and try again.

Hi there guys, i'm new to this stuff, but i have read all the stuff needed to put this usb miner working. The only trouble i have is, the usb miner is working slowly, the hash rate is about 2-3 Gh/s. I've changed the mhz to 150,125, but the results are pretty much the same, arround 4Gh/s. i thought the problem was the hub usb (i use a aukey CB-H19) but i realise that the is more than enough. I run the system (windows 10 64bits) in a virtualization server running vmware.

If someone knows what's happening.