usb 3.0

USB 3.0, released in November 2008, is the third major version of the Universal Serial Bus (USB) standard for interfacing computers and electronic devices. The USB 3.0 specification defined a new architecture and protocol, named SuperSpeed, which included a new lane for a new signal coding scheme (8b/10b symbols, 5 Gbps; also known later as Gen 1) providing full-duplex data transfers that physically required five additional wires and pins, while preserving the USB 2.0-architectur and -protocols and therefore keeping the original 4 pins/wires for the USB 2.0 backward-compatibility resulting in 9 wires (with 9 or 10 pins at connector interfaces; ID-pin is not wired) in total. The new transfer rate, marketed as SuperSpeed USB (SS), can transfer signals at up to 5 Gbit/s with nominal data rate of 500 MB/s after encoding overhead, which is about 10 times faster than High-Speed (maximum for USB 2.0 standard). It is recommended that manufacturers distinguish USB 3.0 connectors from their USB 2.0 counterparts by using blue color for the Standard-A and -B receptacles and plugs, and by the initials SS.USB 3.1, released in July 2013, is the successor specification that fully replaces the USB 3.0 specification. USB 3.1 preserves the existing SuperSpeed operation mode (8b/10b symbols, 5 Gbps), giving it the new label USB 3.1 Gen 1, The USB 3.1 specification introduced an Enhanced SuperSpeed system – while preserving the SuperSpeed-architecture and -protocol – with an additional SuperSpeedPlus-architecture adding a new coding scheema (128b/132b symbols) and protocol named SuperSpeedPlus (aka SuperSpeedPlus USB, for some time period marketed as SuperSpeed+ or SS+) while defining a new transfer mode, called USB 3.1 Gen 2 which can transfer signals at up to 10 Gbit/s over the existing Type-A - and -B, and USB-C fabrics with a nominal data rate of 1212 MB/s after encoding overhead, more than twice the rate of USB 3.0 (aka Gen 1).. The Gen 2 Type-A and Type-B-connectors and -plugs are usually colored as teal blue. Still, the USB 2.0 specification stays implemented based on its own physical layer and architecture.
USB 3.2, released in September 2017, fully replaces the USB 3.1 specification. The USB 3.2 specification added an additional second lane to the Enhanced SuperSpeed system besides other enhancements, so that SuperSpeedPlus USB implements the Gen 2x1 (aka USB 3.1 Gen 2), and the two new Gen 1x2 and Gen 2x2 operation modes while operating on two lanes. The SuperSpeed-architecture and -protocol (aka SuperSpeed USB) still implements the one-lane Gen 1x1 operation mode (aka USB 3.1 Gen 1). Therefore, two-lane operations, namely USB 3.2 Gen 1x2 (10 Gbit/s with nominal data rate of 1 GB/s after encoding overhead) and USB 3.2 Gen 2x2 (20 Gbit/s, 2.422 GB/s), are only possible with Full-Featured USB Type-C fabrics (24 pins). As of 2023, USB 3.2 Gen 1x2 and Gen 2x2 are hardly yet implemented by most products so far. On the other hand, USB 3.2 Gen 1(x1) (5 Gbit/s) and Gen 2(x1) (10 Gbit/s) implementations are quite common now for some years. Again, backward-compatibility is given by the parallel USB 2.0 implementation.

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