They probably use class2/4 memory so...
you'll get around 2-4mb/s sustained transfers.
Make sure you are using usb 2.0 (enable it in bios), update your chipset/usb drivers.
Plug the device directly into the motherboard, don't use a front panel port (lots of cases use cheap low-quality cables), and don't use a non-powered hub like a keyboard or monitor usb port.
|