What is the Difference between usb 2 and usb 3

Difference between usb 2 and usb 3

What is usb 2?

USB 2.0 was released in April 2000, with USB 1.x adding a full speed signaling rate of 12 Mbit / s and a maximum signaling rate of 480 Mbit / s (60 MB / s), also known as high speed or high bandwidth.
The USB specification has been modified by the Engineering Change Notices (ECN).

The very important of these ECNs are included in the USB 2.0 condition package available from USB.org:

  • Mini-A and Mini-B connector
  • Micro-USB Cables and Connectors Specification 1.01
  • C Internship USB Supplement
  • On-the-Go Supplement 1.3 USB On-the-Go allows two USB devices to communicate with each other

Difference between usb 2 and usb 3

without the need for a separate USB host.

• Battery Charging Specification 1.2: Enables high speed communication with a current of up to 1.5 A and a maximum of 5 A current, while charging ports for unconfigured devices.
• Power Link Power Management Supplement ECN, which adds sleep power status

What is USB 3?

The USB 3.0 design was released on 12th November 2008, and its administration was transferred from the USB 3.0 Promoter Group to the USB Implementers Forum and announced at the Super Speed USB Developers Conference on 17th November 2008.

SuperSpeed transfer mode

USB 3.0 adds SuperSpeed transfer mode with associated backward compatible plugs, receivers and cables. SuperSpeed plugs and receptors are marked with a special logo and blue inserts in standard format receptacles.

The Super Speed Bus offers transfer mode at a nominal rate of 5.0 Gbit / s. Its potential depends on a number of aspects, including physical symbol encoding. At 5 Gbit / s signaling rate with 8b / 10b encoding, 10 bits are required to transmit each byte, so the raw throughput is 500 MB / s.

When stream control, packet framing and protocol overhead are considered, broadcasting to applications of 400 MB / s (3.2 Gbit / s) or higher is realistic. Communication full-duplex mode in superspeed transfer; Previous modes were half-duplex, mediated by the host.

Low-power and high-power devices work with this standard, but superSpeed devices can take up to 150 mA and 900 mA, respectively.

USB 3.0 also introduced the UASP protocol, which usually provides faster transfer speeds than the BOT (Bulk-Only-Transfer) protocol.

USB 2.0 VS USB 3.0

When comparing 2.0 and 3.0 there are a only few differences, the transfer rates of data: USB 2.0 offers transfer data rates of 480 Mbps and USB 3.0 offers transfer rates of 4.8 Gbps, which is 10 times faster.
Bus Type Max Transfer Rate of data USB 3.0 Transfer Speed USB 2.0 Transfer Speed

  • PCIe 1.0a 2.5 Gbps 2.5 Gbps 480 Mbps
  • PCIe 2.0/2.1 5 Gbps 4.8 Gbps 480 Mbps
  • PCIe 3.0 8 Gbps 4.8 Gbps 480 Mbps
  • ExpressCard 1.0 2.5 Gbps 2.5 Gbps 480 Mbps
  • ExpressCard 2.0 5 Gbps 4.8 Gbps 480 Mbps

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