If you use desktop or laptop, you must know USB 2.0. Of course, it has been widely used in our life now. USB 2.0 is short for Universal Serial Bus, which is a specification to establish communication between devices and a host controller. This application has effectively replaced a variety of interfaces such as serial and parallel ports. With the help of USb flash drive, you can store pictures or music from desktop or laptop. What’s more, a flash drive is so portable that you can put it in your handbag. As you know, USB 2.0 is used by a lot of people, but have you heard of USB 3.0? Although current versions of Windows do not support USB 3.0, however support is expected for Windows Vista and Windows 7 at a later date via an update or service pack. And the Linux kernel supports USB 3.0 as of version 2.6.31. Anyway, based on some news, it is predicted that USB 3.0 is not likely to go mainstream within a few years. Now that we have the concept of USB 3.0, I think it is necessary to compare current USB 2.0 and USB 3.0. 1. USB release dates USB was developed as an alternative to serial and parallel data transfer protocols. USB 1.0 was introduced in January 1996, which has been a long time before the USB 2.0 specification was released. 2. Major changes in USB 3.0 ?Super speed — New higher signaling rate up to 5Gbps (625MB/sec) ?Dual-bus architecture — Low-Speed, Full-Speed, and High-Speed bus plus Super speed bus ?Asynchronous instead of polled traffic flow ?Dual-simplex simultaneous bi-directional data flow for Super speed instead of half-duplex unidirectional data flow ?Support for streaming ?Fast Sync –N-Go technology ?Support for higher power ?Better power management 3. The Low-Speed, Full-Speed, High-Speed and Super Speed confusion There are 4 distinct data rates - not to be confused with the 4 USB specifications. Each USB specification has a data rate. Actually, USB 2.0 is not always equal to High-Speed. A device labeled USB 2.0 can operate at Full-Speed instead of High-Speed. So people ask whether this confusing labeling will still exist for USB 3.0. The USB 3.0 specification supports the three legacy speeds in addition to Super Speed. This is accomplished by referencing, not replacing, the USB 2.0 specification. Low-Speed, Full-Speed, and High-Speed devices are USB 2.0 compliant but not USB 3.0 compliant, so a USB High-Speed device should not be labeled as a USB 3.0 device. The USB Implementers Forum (USB-IF) has developed logos for each of the four data rates. Thus, you’d better look for these logos according to your specific requirements when buying a USB device. To tell you the truth, it can be known whether your USB 2.0 device is a High-Speed device or not in the Windows Device Manager, although it is not a straightforward exercise. If you are interested in it, you can visit the relevant forum to get more information and help.