USB development history

① Earlier version:

USB 0.7: Released in November 1994;

USB 0.8: Released in December 1994;

USB 0.9: Released in April 1995;

USB 0.99: Released in August 1995;

USB 1.0 RC: Released November 1995.

②USB 1.0: Released in January 1996

The data transfer rate is 1.5Mbit/s (Low-Speed). No prediction and pass detection functions. Only very few appear on the market.

③USB 1.1: Released in September 1998

Fixed issues found in version 1.0, mostly related to USB Hubs. The earliest adopted revision. The data transfer rate is 12Mbit/s (Full-Speed).

④USB 2.0: Released in April 2000

Increase the higher data transmission rate of 480Mbit/s (now called Hi-Speed), but limited by the BOT transmission protocol and NRZI encoding method, the actual maximum transmission speed is only about 35MByte/s. USB OTG (On-The-Go) is a supplementary standard of the USB2.0 specification.

⑤USB 3.0: Released in November 2008

The speed has been greatly increased from 480Mbps to 5Gbps, and the USB 3.0 socket is usually blue and is backward compatible with USB 2.0.

⑥USB 3.1: Released on July 31, 2013

The transmission speed is increased to 10Gb/s, which is twice as fast as the 5Gb/s of USB3.0, and is backward compatible with USB 2.0/1.0, and the power supply can be up to 100W.

⑦USB 3.2

In the existing USB Type-C data online implementation of dual channels, using a USB 3.2 host to connect a USB 3.2 storage device, the transmission speed of the two channels can be 10Gb/s, which is theoretically quite close to 20Gb/s.

⑧USB 4: Released on September 3, 2019

Using the Thunderbolt 3 protocol specification, Thunderbolt 3 devices will be compatible with USB 4, and the existing 3.2 and 2.0 are also backward compatible. The speed is doubled to a total transfer speed of 40Gb/s for both channels.

USB version

The current official main version numbers of USB-IF (USB-IF: USB Implementers Forum, USB Standardization Organization) are only USB 2.0 and USB 3.2. There are only two main versions of the USB standardization organization, but now the USB standard is divided into the following versions according to the speed grade and connection method: USB 1.0, 1.1, 2.0, 3.0, 3.1, 3.2.