• <More on Intel.com

Intel Universal Serial Bus (USB) Frequently Asked Questions (FAQ)

SuperSpeed USB 3.0 operates at 5 Gbps as compared to High-Speed USB 2.0, which operates at 480 Mbps.

  • When was the final USB 3.0 specification released?

The spec was released in November 2008.

  • Who developed USB 3.0?

USB 3.0 was developed by six industry-leading companies, collectively named the USB 3.0 Promoter Group: Hewlett-Packard, Intel, Microsoft, NEC (now known as Renesas Electronics), ST-NXP Wireless (now known as ST-Ericsson), and Texas Instruments.

  • Does SuperSpeed USB 3.0 supersede High-Speed USB 2.0?

No, SuperSpeed USB 3.0 extends USB by adding a dual-simplex 5 Gbps capability that can be used by devices that need even higher performance than what is already available with High-Speed USB 2.0. SuperSpeed USB is complementary to High-Speed USB and most platforms are expected to support both SuperSpeed USB and High-Speed USB.

  • Is there a difference between High-Speed USB and USB 2.0? Which is the correct nomenclature?

There is a difference in High-Speed USB and USB 2.0—the USB 2.0 specification covers 480 Mbps, 12 Mbps, and 1.5 Mbps speeds, while "High-Speed USB" refers to just the 480 Mbps portion of the USB 2.0 specification. We now use the term "USB" to refer to the 12Mbps and 1.5Mbps speeds.

  • What is USB On-the-Go?

USB On-the-Go, available for High-Speed USB 2.0, addresses the growing need for mobile interconnectivity by allowing a USB peripheral to communicate directly with another USB peripheral. With the introduction of SuperSpeed USB 3.0, USB On-the-Go will soon be available for future mobile devices supporting 5 Gbps capability.

  • What are the “SuperSpeed” and "High-Speed" logos, and what do they represent?

These logos are trademark-protected logos owned by the USB-IF for use by qualified licensees. The logos are a guarantee to the consumer that the product has undergone compliance testing for quality.

  • Where can I get more information on USB and the logos I see on USB products?

USB-IF web site is the definitive source for all information pertaining to USB and the product certification program.

  • How many devices can be connected to one host device?

Each host controller can support up to 127 devices. A host device may contain multiple host controllers.

  • What if I have additional questions?

The USB-IF maintains a frequently asked questions web page.

  • Are any technical books available that discuss USB?

USB Design by Example, Second Edition by John Hyde provides the expert knowledge and skills you need to design and implement a wide range of USB devices.