Universal Serial Bus (USB) 3.0 is the latest specification of the USB standard, introduced in August 2008 by a partnership of developers led by Intel. The protocol allows for data transfer speeds up to 5.0 gigabits per second (Gbits/s), or 625 Megabytes per second (MB/s), about ten times faster than USB 2.0.
USB 1.0 technology was introduced in 1996 and has undergone several iterations, improving in transfer speed with each new standard. To date, the standards are as follows:
- USB 1.0 Low Speed 1.5 Mbits/s
- USB 1.1 Full Speed 12 Mbits/s (1.5 MB/s)
- USB 2.0 High Speed 480 Mbits/s (60 MB/s)
- UBS 3.0 SuperSpeed 5.0 Gbits/s (625 MB/s)
Human interface devices, such as keyboards and mice, require low bandwidth and can operate with USB 1.0, while subsequent protocols are used for data transfer between computers and peripheral devices such as external hard drives, printers, scanners, fax machines and backup units. Digital cameras, cell phones, personal digital assistants (PDAs) and game consoles are among the plethora of other electronic devices that also make use of USB.
With greater demands for transferring larger files at faster speeds, USB 3.0 was promised to be a welcome improvement from 2.0 technology and USB might not be a bottleneck for data transfer. Internal hard drives could be playing catch-up until "SATA 6 Gb/s" (the next generation SATA with transfer rates of 6 gigabits per second) and solid-state drives become widespread. In the meantime, SATA drives with maximum data transfer rates of 300 MB/s (3 Gb/s) will only be half as fast as USB 3.0, assuming it matures to its full theoretical potential.
With even homeowners are surpassing the 1 terrabyte boundary, and many at home and at work using external drives for full drive backups, faster transfer speeds are important. External enclosures using USB 3.0 would reduce backup times considerably, improving productivity and efficiency. Transferring graphic contents from digital movie and camera flash cards is another area where the average person could see a drastic improvement with the improved technology.
USB 3.0 achieves its high transfer rates by using four additional wires in the data cable, for a total of six wires. It supports full-duplex communication, or the ability to send and receive data simultaneously, and is power efficient. Most importantly, it is backward compatible with USB 2.0 devices, although to achieve 3.0 speeds, a 3.0-compatible device and cable must be used.