USB 3.0, the latest version of USB (Universal Serial Bus), provides better speed and more efficient power management than USB 2.0. USB 3.0 is backward compatible with USB 2.0 devices; however, data transfer speeds are limited to USB 2.0 levels when these devices inter-operate.
Comparison chart
| USB 2.0 | USB 3.0 | |
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| Released | April 2000 | November 2008 |
| Speed | High Speed or HS, 480 Mbps (Megabits per second) | 10 times faster than USB 2.0. Super Speed or SS, 4.8 Gbps (Giga bits per second) |
| Signaling Method | Polling mechanism i.e can either send or receive data (Half duplex) | Asynchronous mechanism i.e. can send and receive data simultaneously (Full duplex) |
| Price | For a similar product, the USB 2.0 version is generally less expensive than it's USB 3.0 version. | For a similar product, the USB 3.0 version is generally more expensive than it's USB 2.0 version. |
| Power Usage | Up to 500 mA | Up to 900 mA. Allows better power efficiency with less power for idle states. Can power more devices from one hub. |
| Number of wires within the cable | 4 | 9 |
| Standard-A Connectors | Grey in color | Blue in color |
| Standard-B Connectors | Smaller in size | Extra space for more wires |
| Max Cable length | 5 meters | 3 meters |
