USB - Wikipedia, the free encyclopedia
USB supports the following signaling rates: The terms speed and bandwidth are used interchangeably. "high-" is alternatively written as "hi-".
A low-speed rate of 1.5 Mbit/s (~183kB/s) is defined by USB 1.0. It is very similar to full-bandwidth operation except each bit takes 8 times as long to transmit. It is intended primarily to save cost in low-bandwidth human interface devices (HID) such as keyboards, mice, and joysticks. The full-speed rate of 12 Mbit/s (~1.43 MB/s) is the basic USB data rate defined by USB 1.1. All USB hubs support full-bandwidth.
A high-speed (USB 2.0) rate of 480 Mbit/s (~57 MB/s) was introduced in 2001. All hi-speed devices are capable of falling back to full-bandwidth operation if necessary; i.e. they are backward compatible with USB 1.1. Connectors are identical for USB 2.0 and USB 1.x.
A SuperSpeed (USB 3.0) rate of 4800 Mbit/s (~572 MB/s). The written USB 3.0 specification was released by Intel and partners in August 2008. The first USB 3 controller chips were sampled by NEC May 2009[55] and products using the 3.0 specification arrived beginning in January 2010.[56] USB 3.0 connectors are generally backwards compatible, but include new wiring and full duplex operation.
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