USB 3.1 Gen 1 and 3.1 Gen 2 – What’s the Difference?

Universal Serial Bus, or USB, is one of the most widely used protocols in technology. Most people, from experienced techies to the average consumer, use USB almost daily as it is incorporated into billions of devices worldwide. Over the years, multiple USB specifications have been released, each with improved speeds and efficiency. Particularly, with recent widespread technological advances and production of progressively complex devices, a USB spec that offered a larger bandwidth and quicker throughput performance was required. To answer this demand, the USB 3.0 spec was released in 2008.  This new version of the USB spec allowed for a vast increase of data transfer rates–up to 5 Gbps.

Five years later, in 2013, came a new revision of the USB specification that could transfer up to 10 Gbps, twice that of USB 3.0. With the latest revision, there also came a name change to the preliminary USB 3.0 protocol; USB 3.0 became USB 3.1 Gen 1 and the successor was named USB 3.1 Gen 2.

USB 3.1 Gen 1 vs Gen 2: Data Transfer Rates

You might be wondering what are the differences between USB 3.1 Gen 1 and USB 3.1 Gen 2? The most apparent difference is the data transfer rates. As mentioned before, USB 3.1 Gen 1 can transfer data up to 5 Gbps, while USB 3.1 Gen 2 can transfer data up to10 Gbps. USB 3.1 Gen 2 is capable of supporting all data transfer needs, including audio and video data transfers, and has improved data decoding. Both Gen 1 and Gen 2 offer power management that allows for increased power efficiency that does not require device polling. They are also both backwards compatible with USB 2.0, while Gen 2 works with existing USB 3.0 hubs and devices.

USB and the Addition of Power Delivery

Around the time of the release of the USB 3.1 Gen 2 spec, USB Type-C cables and connectors were starting to be introduced, and now they are increasingly used together in newer designs. Many of the future cables will incorporate the performance of USB 3.1 Gen 1 and Gen 2 with the convenience of the versatile USB Type-C connector and the enhanced charging capabilities of USB Power Delivery.  For more on USB Type-C and USB Power Delivery see our post  about the Impact of the Type-C Connector and USB Power Delivery.

How Total Phase Supports USB Tests

Beagle USB 5000 v2 SuperSpeed Protocol AnalyzerTotal Phase offers multiple development tools suited for testing USB. For example, for the USB 3.1 Gen 1 spec, we offer the Beagle USB 5000 v2 SuperSpeed Protocol Analyzer, which can non-intrusively monitor Super, High, full, and low speed USB data. In conjunction with our Data Center Software, the Beagle USB 5000 v2 analyzer can capture USB 3.1 Gen 1 (or USB 2.0) communication in real time, without needing to capture, download, and parse data separately. Our Data Center Software also offers instant class-level decoding, and LiveFilter technology to search and filter for specific data patterns to quickly find bugs and bug sources. The Standard edition has a 2 GB buffer and offers a USB 2.0 downlink. For even faster download speeds, the Ultimate edition offers a 4 GB buffer and a USB 3.1 Gen 1 downlink.

USB Power Delivery

Along with the Beagle USB 5000 v2 SuperSpeed analyzer, we also have introduced new products for USB Power Delivery and Type-C cable testing Power Delivery Analyzerthat support USB 2.0 to USB 3.1 Gen 2 data rates. Our USB Power Delivery Analyzer non-intrusively monitors Power Delivery (PD) traffic on the CC1 and CC2 lines of Type-C compatible devices and in turn displays the power negotiation process and message decoding with our Data Center Software. By using both the hardware and software, you can capture real-time PD data and measure VBUS and VCONN voltage and current levels, which can be graphically displayed on your dashboard. You can also monitor the USB data roles, DisplayPort, or other Type-C Alternate Modes. These tools give you advanced insight into Type-C receptacle signals and power level negotiations, so debugging is quick and easy.

Advanced Cable Tester v2

Our Advanced Cable Tester v2 is crucial for any company creating or integrating Type-C cables into their products. Because of the high-power levels and increased complexity of the cable itself, there is higher probability of error and failure. The Advanced Cable Tester  provides comprehensive test coverage for cable safety and quality. It performs safety checks through testing and validation of signal continuity to prevent VBUS shortages. It also analyzes DCR and IR Drop to certify that VBUS and GND pins are supplying the required current and checks for E-Marker accuracy by comparing captured data to advertised data. The Advanced Cable Tester v2 also offers signal integrity testing with corresponding eye diagrams. Signal integrity checks are performed for High-Speed D+/D– (512 Mbps) and SuperSpeed pairs (5 Gbps, 10 Gbps, up to 12Gbps) to verify they meet the relevant specifications.

Here at Total Phase, we continually strive to provide the most relevant, top-quality testing and development tools so you can produce products that are reliable and safe. Our well-rounded and ever-progressing line of products guarantees your ability to keep up with the latest advances in USB.