Question: how to tell difference between usb 2 and 3?
Answer: Actually, it is not difficult to tell their physical difference. The USB 2.0 Connectors is colored white or black inside, while the USB 3.0 is colored blue inside. So if you want to find out whether the USB port on your computer or USB flash drive is 2.0 or 3.0, you can distinguish them by the USB port color inside.