USB Standard
USB 3.1
USB 3.1 introduced 10 Gbps operation while retaining the earlier 5 Gbps mode, and both capabilities were later folded into the USB 3.2 family.
Overview · Naming · Compatibility · Articles
Related: USB Standards · USB 3.0 · USB 3.2
USB 3.1 overview
USB 3.1 kept the 5 Gbps mode from USB 3.0 and added a new 10 Gbps mode, creating the Gen 1 and Gen 2 names later carried into USB 3.2.
| Maximum data rate introduced | 10 Gbps |
|---|---|
| 5 Gbps mode | USB 3.1 Gen 1 |
| 10 Gbps mode | USB 3.1 Gen 2 |
| Current 3.x relationship | The USB 3.2 specification absorbs the earlier USB 3.1 specification |
| Connector relationship | Supported across compatible legacy SuperSpeed connectors and USB-C implementations |
| Current status | Historical revision; 5 Gbps and 10 Gbps USB remain current within USB 3.2 |
Sources: USB-IF USB 3.1 language usage guidelines, USB-IF USB 3.2 Revision 1.1 Base Specification, and USB-IF USB 3.1 Legacy Cable and Connector Specification.
USB 3.1 Gen 1 vs Gen 2 naming
USB 3.1 called the existing 5 Gbps mode Gen 1 and the new 10 Gbps mode Gen 2, while current consumer guidance favors USB 5Gbps and USB 10Gbps.
| USB 3.1 term | Data rate | Earlier or later specification name | Current consumer-facing name |
|---|---|---|---|
| USB 3.1 Gen 1 | 5 Gbps | Originally USB 3.0; later USB 3.2 Gen 1 / Gen 1x1 | USB 5Gbps |
| USB 3.1 Gen 2 | 10 Gbps | Introduced with USB 3.1; later USB 3.2 Gen 2 / Gen 2x1 | USB 10Gbps |
Sources: USB-IF USB 3.1 language usage guidelines, USB-IF USB Data Performance Language Usage Guidelines, and USB-IF USB 3.2 Revision 1.1 Base Specification.
USB 3.1 compatibility
USB 3.1 devices can use faster or slower USB 3.x connections, but the negotiated speed is limited by the least capable host, device, cable, hub, or adapter.
| Connection | What happens | Main limit |
|---|---|---|
| USB 3.1 Gen 2 device + 10 Gbps host + 10 Gbps cable | Can operate at up to 10 Gbps | All parts of the path must support the Gen 2 rate |
| USB 3.1 Gen 2 device + 5 Gbps USB 3.x host or cable | Falls back to up to 5 Gbps | The 5 Gbps host or cable |
| USB 3.1 Gen 1 device + 10 Gbps-capable host | Works, but remains limited to its 5 Gbps device capability | The Gen 1 device |
| USB 3.1 device + USB 2.0 path | Can fall back to USB 2.0 when the device and physical connection support the legacy path | Up to 480 Mbps on USB 2.0 |
| USB 3.1 Gen 2 over USB-A | 10 Gbps is possible with compatible SuperSpeed 10 Gbps host, device, and cable hardware | The connector alone does not determine the USB generation |
| USB 3.1 over USB-C | May run at USB 2.0, 5 Gbps, or 10 Gbps depending on the implementation | USB-C shape does not guarantee Gen 2 capability |
| Hub, dock, or adapter in the path | The connection negotiates to the best mode supported end to end | The slowest host, hub, dock, adapter, cable, or device |
Sources: USB-IF USB 3.2 Revision 1.1 Base Specification, USB-IF USB 2.0/USB 3.2 interoperability test procedures, USB-IF USB 3.1 Legacy Cable and Connector Specification, and USB-IF USB Type-C Cable and Connector Specification.
USB 3.1 articles
Browse guides about USB 3.1 speeds, compatibility, USB-C hardware, storage, adapters, and how USB 3.1 naming relates to later USB standards.
