Making a Home for More USB Devices
Most recent desktop computers feature six or more USB 2.0 ports, so there’s almost always enough places to plug in your favorite USB peripherals. However, with USB being used for everything from digital cameras and scanners to external hard disks, printers, and flash drives, notebook computers, which often feature as few as two USB 2.0 ports, often don’t have enough to go around. Fortunately, the solution is simple: buy an external USB hub. A USB hub plugs into a single port on your system, but provides four (or more) USB ports for other devices, and are usually available for $20–40.
As you’re shopping, watch out for two potential problems:
- Avoid USB 1.1 hubs (often identified simply as "USB" hubs). A USB 1.1 hub has a top speed of only 12Mbps, versus 480Mbps for USB 2.0. Plugging a USB 2.0 device into a USB 1.1 hub slows it down to USB 1.1 speeds (up to 60 times slower!).
- Avoid bus-powered USB hubs. A bus-powered hub reduces the total power available from a USB port (500mA) down to 100mA per port. Many devices, 500mA of power, and some might fail catastrophically if plugged into a low-powered hub. Make sure the hub you buy includes an AC adapter, enabling all ports to provide the full 500mA of power needed by some devices.