Well you will get much reduced speeds on USB a lot of the time as the 12MBit is shared across the hub
Transfer speed
USB supports three
data rates.
- A Low Speed rate of 1.5 Mbit/s (183 KiB/s) that is mostly used for Human Interface Devices (HID) such as keyboards, mice and joysticks.
- A Full Speed rate of 12 Mbit/s (1.4 MiB/s). Full Speed was the fastest rate before the USB 2.0 specification and many devices fall back to Full Speed. Full Speed devices divide the USB bandwidth between them in a first-come first-served basis and it is not uncommon to run out of bandwidth with several isochronous devices. All USB Hubs support Full Speed.
- A Hi-Speed rate of 480 Mbit/s (57 MiB/s). (Commonly called USB 2.0)
(Taken frm
www.wikipedia.com)