USB3.1 USB-C: One Port, Two Jobs
The single connector carries data and power independently. Understanding the split prevents most USB-C confusion.
Quick Answer
| Capability | Port A | Port B | Both on one port? |
|---|---|---|---|
| Data at 5 Gbps | Yes | No | Yes, if the port supports both |
| Data at 10 Gbps | No | Yes | Yes |
| Charging | Basic | Power Delivery | Depends on the port |
| Video | No | Maybe, Alt Mode | Separate from data rate |
How the Roles Split
Data lanes
The generation governs data. A hub shares that bandwidth across its ports.
Power path
Charging negotiates separately. PD ports supply far more than basic USB power.
Alt Mode
Video over USB-C is an additional mode, not part of the data rate.
Hub implication
A hub multiplies ports but not bandwidth, and not power.
Practical Consequences
- Check both data and power specs when choosing a port.
- Do not expect a data hub to charge a laptop.
- Do not expect a charging port to carry data.
- Read the hub’s specification for per port figures.
- Test the workload before a permanent install.
Real-World Applications
- Single port laptops needing everything.
- Docks at fixed desks.
- Charging plus sync stations.
- Test benches with mixed devices.
Related Guides
For the data tier, read 3.1 USB-C. For hub bandwidth, see USB 3.0 hub. For powered hubs, start with hub USB USB-C.
FAQ
Does USB 3.1 mean fast charging?
No. Data speed and charging power are separate specifications.
Can one port do 10 Gbps and charge?
Yes, on ports that support both data and Power Delivery.
Does a hub share charging power?
Bus powered hubs share a small budget. Powered hubs have more.
Is video part of USB 3.1?
No. Video requires DisplayPort Alt Mode support on the port.