|The maximum transfer rate for USB 2.0 is 480 Mbps.
USB 3.0 transfer rate is over 10x faster than 2.0 with a top speed of 5.0 Gbps. Like computer networks USB will run to the device in your installation. So to achieve this speed will require a host controller, cables and all devices to be USB 3.0 compliant.
Therefore, USB 3.0 is downward compliant