USB 3.1 Cable: Gen 1, Gen 2 and What Changed
USB 3.1 is the most confusing name in the standard. It refers to two different speeds depending on the generation suffix, and the suffix is the part listings most often leave out.
Quick Answer
USB 3.1 Gen 1 is 5 Gbps, identical to the original USB 3.0. USB 3.1 Gen 2 is 10 Gbps and needs cabling built and certified for that rate. For 10 Gbps, check that the listing states Gen 2 or 10 Gbps, keep passive length short and confirm both devices support the rate. Current naming calls Gen 1 USB 3.2 Gen 1 and Gen 2 USB 3.2 Gen 2.
Naming Timeline
| Original name | Renamed | Current name | Rate |
|---|---|---|---|
| USB 3.0 | USB 3.1 Gen 1 | USB 3.2 Gen 1 | 5 Gbps |
| USB 3.1 | USB 3.1 Gen 2 | USB 3.2 Gen 2 | 10 Gbps |
| USB 3.2 | USB 3.2 Gen 2×2 | USB 3.2 Gen 2×2 | 20 Gbps |
Three generations, two rates, and the name has been reused. This is why the bare phrase USB 3.1 cable tells you nothing about speed.
Connectors Available
- USB-A to USB-B 3.0, for scanners, docks and enclosures.
- USB-A to USB-C, the most common desktop pairing.
- USB-C to USB-C, needed for 10 Gbps and above.
- USB-A to Micro-B 3.0, for portable drives.
What 10 Gbps Requires
A rated cable
All high speed pairs present, with controlled impedance. Ordinary USB 3.0 cables may negotiate 10 Gbps and then fail under sustained load.
Short length
Passive 10 Gbps cables are dependable to roughly 1 to 2 m. Beyond that, active or optical cables are needed.
Both ends capable
The host port and the device must both support 10 Gbps. A 10 Gbps cable on a 5 Gbps port runs at 5 Gbps.
Real-World Applications
- Connecting an NVMe enclosure at 10 Gbps.
- Driving a capture device that needs steady high throughput.
- Faster project transfer between a laptop and a desktop drive.
- Replacing a mislabelled cable that silently limited a drive to 5 Gbps.
Related Guides
For port colour conventions, read USB 3.1 colour. For connector combinations, see USB 3.1 type A and type C. For testing the result, start with how to check a USB 3 port.
FAQ
Is a USB 3.1 cable faster than USB 3.0?
Only if it is Gen 2. Gen 1 is the same 5 Gbps as USB 3.0.
How do I know which generation a cable is?
The listing should state the rate. If it says only USB 3.1, assume 5 Gbps until proven otherwise.
Does a USB 3.1 cable carry video?
Not by itself. Video requires DisplayPort Alt Mode support on the host and a compatible cable and device.
What is the maximum length for 10 Gbps?
About 1 to 2 m passive. Longer runs need active cables.