The Introduction of SuperSpeed USB
Throughout the years, the SuperSpeed USB specification has undergone many changes due to its support for increased bit rates and implementation of a multi-lane operation. However, the ongoing rebranding efforts to keep with these changes has oftentimes caused confusion in the industry.
We’ll provide some background on the various name changes for SuperSpeed USB, and provide an update on the current USB naming and branding that USB-IF has released in the wake of the USB4 introduction.
The first SuperSpeed USB specification, USB 3.0, was released in 2008, and it most notably supported increased speeds up to 5 Gbps, a vast improvement from USB 2.0 which supported 480 Mbps. Other improvements SuperSpeed USB introduced included:
- Increased bus power and current draw
- Improved power management
- Full duplex data communications
- Link Training and Status State Machine (LTSSM)
- Interrupt driven, instead of polling
- Streaming interface for more efficient data transfers
SuperSpeed USB was a significant achievement for USB technology since it introduced many new capabilities that were simply not possible before. Now, users could stream their data 10 times faster with reduced power consumption.
USB 3.0 to USB 3.1 to USB 3.2
In 2013, USB-IF introduced a new SuperSpeed+ transfer mode, USB 3.1, which supported up to 10 Gbps on one lane. To remain consistent in the naming, USB-IF rebranded the original USB 3.0 specification as USB 3.1 Gen 1 and named the newest USB SuperSpeed+ release to be USB 3.1 Gen 2. Products listed as USB 3.1 Gen 1 were capable of signaling up to 5 Gbps while products labeled USB 3.1 Gen 2 were capable of the full 10 Gbps released in the updated USB 3.1 specification.
In 2017, USB-IF introduced yet another speed increase to the SuperSpeed USB specification, USB 3.2, now offering support for 10 Gbps over 2 lanes for a total bandwidth of 20 Gbps. Achieving this speed was possible due to the USB 3.2 standard supporting multi-lane operation within a Type-C cable. With this new ability, this prompted USB-IF to again rebrand to create a more homogenized naming standard between the different SuperSpeed USB performance capabilities. Now, USB 3.1 Gen 1 became to USB 3.2 Gen 1, USB 3.1 Gen 2 changed to USB 3.2 Gen 2x1, and the new speed capable under the USB 3.2 version of the specification was named USB 3.2 Gen 2x2, with x2 referring to the number of lanes.
Today, the final USB 3.2 specification comprises of all prior 3.0 and 3.1 specifications and encompasses all three speeds: 5 Gbps, 10 Gbps, and 20 Gbps. For marketing and branding purposes, the SuperSpeed USB packaging logos include these performances for easier adoption by consumers:
- USB 3.2 Gen 1 for signally up to 5 Gbps: SuperSpeed USB
Image by USB.org
- USB 3.2 Gen 2 for signally up to 10 Gbps: SuperSpeed USB 10 Gbps
Image by USB.org
- USB 3.2 Gen 2x2 for signally up to 20 Gbps using 2 lanes: SuperSpeed USB 20 Gbps
Image by USB.org
Summary of SuperSpeed USB Name Changes
New Changes with USB4
In 2019, the USB Promoter Group announced the USB4 specification, which offers a substantial increase in signaling speed – up to 40 Gbps using a dual lane operation within a Type-C cable. With this newly introduced USB spec, it will provide a new opportunity for USB-IF to create a clear brand that distinctly indicates USB performance moving forward.
Like SuperSpeed+ USB, USB4 will also support 20 Gbps, but with the new USB4 branding, it will be clear which USB4 cables support 20 Gbps, and which support 40 Gbps, as noted by the following packaging logos:
Images by USB.org
The USB4 specification is officially available for USB developers to utilize within their product developments, and will be compatible with the widely adopted USB Type-C cable. Along with its ability to signal up to 40 Gbps, this new USB technology also allows for multiple data and display protocols to efficiently share the maximum aggregate bandwidth, and includes backwards compatibility with USB 3.2, USB 2.0, and Thunderbolt 3.
Total Phase Supports Development of USB
Total Phase offers a variety of tools that support the debugging and development of USB, including protocol analyzers and cable testing solutions. Our line of USB protocol analyzers can non-intrusively monitor USB bus data in real time with support for USB specifications ranging from USB 1.0 supporting 12 Mbps, USB 2.0 supporting 480 Mbps, to USB 3.2 Gen 1 supporting 5 Gbps.
Our USB Power Delivery Analyzer can monitor Power Delivery (PD) communication occurring on the CC lines within a Type-C cable so finding any issues with messaging, power negotiation, or alternate mode negotiation can easily be discovered. This tool supports the USB 3.2 Gen 2x2 spec.
Additionally, to test the overall cable performance, our Advanced Cable Tester v2 comprehensively tests a variety of USB cables for quality and safety checks including continuity testing, DC resistance testing, E-marker verification, and signal integrity testing.
For more information on how our USB tools can help with your projects, please email us at sales@totalphase.com.