USB 3.0 Hub: Shared Bandwidth and Current
A USB 3.0 hub provides 5 Gbps in total, divided by however many ports are busy. The current budget matters just as much.
Quick Answer
| Hub type | Bandwidth | Current | Can run |
|---|---|---|---|
| Bus powered | 5 Gbps shared | 900 mA shared | Peripherals, one flash drive |
| Self powered | 5 Gbps shared | Full current per port | Drives, heavier devices |
| With charging ports | 5 Gbps shared | Higher on charge ports | Peripherals plus phone charging |
| USB 2.0 hub | 480 Mbps shared | 500 mA shared | Legacy devices only |
Bandwidth in Practice
One busy device
Uses most of the link, up to the device’s own limit.
Two busy devices
Split the 5 Gbps roughly in half.
Input devices
Cost nothing measurable.
Network or display on the hub
Competes with storage for the same link.
Power in Practice
- Count the devices that draw real current.
- Choose self powered if any external drive is involved.
- Check the per port figure, aiming for 900 mA or more.
- Watch for warm connectors, which indicate resistance.
- Test a large transfer to a drive before relying on it.
Real-World Applications
- Adding ports to a laptop with few sockets.
- Desk peripherals at a fixed position.
- Card readers and dongles at a workstation.
- Test equipment on a bench.
Related Guides
For USB-C hubs, read USB Type-C hub. For mini hubs, see mini gadget USB hub. For current budgets, start with USB-C power hub.
FAQ
Does every port get full speed?
No. They share one 5 Gbps upstream link.
Can a bus powered hub run a drive?
One SSD sometimes. Mechanical drives need self powered.
Does the hub need drivers?
Usually not for USB ports.
Is a 3.0 hub faster than 2.0?
Yes, ten times in principle, provided the devices can use it.