Comparing USB 2.0 and USB 3.0

The popular USB standard continues to evolve. SuperSpeed USB (USB 3.0) is the next advancement in USB technology. It is similar to earlier versions of USB as it supports data transfer between a host computer and devices. It offers data transfer rates up to 10 times faster than Hi-Speed USB (USB 2.0), backward compatibility with previous generations of USB, optimized power efficiency and increased power delivery. Here is a side-by-side comparison between Hi-Speed USB and SuperSpeed USB.

USB 2.0
Technology name: Hi-Speed USB
Specification released April 2000
Data transfer rate of 480 Mbps, 40 times faster than previous generation
Real-world speed: Downloading a 25 GB HD movie from your home server to your notebook takes about 15 minutes
Contains four wires inside the cable
Unidirectional
Backward compatible with previous generations of USB
Power delivery for Hi-Speed USB Devices: 500 mA.
Power-management mechanisms to allow aggressive management of I/O power consumption
Hi-Speed USB devices do not need to be altered to comply with SuperSpeed USB, because SuperSpeed USB is backward compatible.
Look for Certified Hi-Speed USB logo to ensure USB host or device has passed Hi-Speed compliance tests

USB 3.0
Technology name: SuperSpeed USB
Specification released Nov. 2008
Data transfer rate up to 5 Gbps, 10 times faster than Hi-Speed USB data transfer rates
Real-world speed: Downloading a 25 GB HD movie from your home server to your notebook takes about 60 seconds
Contains nine wires; five additional wires
Bidirectional
Backward compatible with previous generations of USB
Power delivery for SuperSpeed USB devices: 900 mA.
Extended battery life of host; improved power delivery for SuperSpeed USB devices
To achieve SuperSpeed USB data transfer speeds, both host and device must be SuperSpeed USB-enabled and SuperSpeed cabling must be used.
Look for Certified SuperSpeed USB logo to ensure USB host or device has passed SuperSpeed USB compliance tests