USB 3.0 is the third major version of the USB standard for interfacing computers and electronic devices. Among other improvements, USB 3.0 adds the new transfer mode super speed (SS) that can transfer data at up to 5 Gbit/s (625 MB/s), which is about ten times faster than the usb 2.0 standard.
USB 3.0 connectors are usually distinguished from their USB 2.0 counterparts by blue color-coding of the receptacles and plugs, and the initials SS.
The new USB 3.0, while maintaining compatibility with the USB 2.0 also provides several enhancements to the following features:
- Transfer speed – added a new transfer type called Super Speed or SS, 5 Gbit/s .
- Increased bandwidth – instead of one-way communication, USB 3.0 uses two unidirectional data paths: one to receive data and the other to transmit.
- Power management – U0 through U3 link power management states are defined.
- Improved bus utilization – a new feature is added to enables the host quickly identify devices.
- Support to rotating media – bulk protocol is updated with a new feature called Stream Protocol that allows a large number of logical streams within an Endpoint.