there is a USB device that state a speed of:
Transfer rates of 480 Mbps (HiSpeed) / 12Mbps (FullSpeed)
what soes it mean? why there is a "HiSpeed" & a "FullSpeed"?
& what will be the speed for transfering 1Gbyte?
What speed you get depends on what connectors the USB device and your computer has. This is because USB 2.0 is backwards compatible with USB 1.0 and will list both speeds as they are standards it will work at.