In this guide
A USB hub is a device that turns one USB port on your computer into several, letting you connect multiple peripherals at the same time through a single upstream connection to your host machine.
- You use a self-powered hub for external drives or other high-power devices
- Your hub matches the USB version of your port (e.g., USB 3.0 hub on a USB 3.0 port)
- You stick to low-bandwidth devices like mice and keyboards on a bus-powered hub
- You connect power-hungry devices to a bus-powered (passive) hub
- You chain multiple bus-powered hubs together
- You use a USB 2.0 hub on a USB 3.0 port and expect full 3.0 speeds
How a USB Hub Works
A USB hub contains an internal chipset that manages communication between one upstream port (connected to your PC or laptop) and several downstream ports (connected to your devices). Your computer still sees a single USB connection; the hub’s chipset handles splitting data and power across all attached peripherals.
All devices on a hub share the bandwidth of that single upstream port. A USB 3.0 port offers up to 5 Gbps — but plug in three storage drives at once and they compete for that same pool of bandwidth. For more detail, see the USB hub overview on Wikipedia.
Self-Powered vs Bus-Powered Hubs
This is the most important distinction when choosing a hub.
- Bus-powered (passive): draws power from your computer’s USB port. Limited to about 500 mA (USB 2.0) or 900 mA (USB 3.0) total across all ports. Fine for mice, keyboards, and flash drives.
- Self-powered (active): plugs into a wall outlet for dedicated power. Can supply full power to each port independently, making it safe for external hard drives, webcams, and charging accessories.
Never daisy-chain bus-powered hubs. Each link in the chain further dilutes available power and can cause devices to disconnect or fail to mount.
USB Version Compatibility
| Hub Version | Works? | Max Speed | Note |
|---|---|---|---|
| USB 3.0 hub on USB 3.0 port | Yes | 5 Gbps | Best match for fast drives |
| USB 2.0 hub on USB 3.0 port | Yes | 480 Mbps | Speed capped at USB 2.0 limit |
| USB 3.0 hub on USB 2.0 port | Yes | 480 Mbps | Port is the bottleneck |
| Bus-powered hub with external drive | No | — | Insufficient power |
USB-C Hubs and Multiport Adapters
Many modern laptops only have USB-C ports, so USB-C hubs have become common. These work the same way internally but often add HDMI, SD card slots, and Ethernet alongside USB-A ports. If you’re working with a USB-C setup, check out whether USB-C can connect to HDMI and what to do if your USB-C to HDMI connection isn’t working for related guidance.
Bottom line: A USB hub is a straightforward way to expand your available ports, but performance depends on choosing the right type. Use a self-powered hub for anything that needs reliable power or fast data transfer, match your hub’s USB version to your port, and keep bandwidth-heavy devices on separate connections where possible.