30 Hardware and Windows Tips in 30 Days Tip 9: Solving a USB Port Shortage
Short of USB ports? Discover the best ways to add more ports without sacrificing performance or compatibility.
How many USB ports are enough? With everything from webcams, scanners, and printers to mice, keyboards, flash drives, and card readers plugging into USB ports, the odds are good the answer is "more." There are a variety of ways to add more ports, but some are better than others.
Before You Add, Implement
If you built your own system, or if your system uses a standard motherboard, you may have some 'hidden' USB ports on your motherboard that you're not using. Most systems have headers for two or more USB ports that could be front or rear-mounted, but there's no guarantee the header cables have been installed.
Check your system or motherboard documentation to determine if all of the motherboard's USB headers are connected to USB header cables. If not, check with your vendor or a third-party source for USB header cables. Since virtually all USB ports on recent motherboards are USB 2.0 compliant, make sure the header cable you buy will work at full USB 2.0 speed. Most header cables are designed to use an empty expansion slot bracket at the rear of the system.
Need More Ports? Cards versus Hubs
If all of your system's USB port headers are already in use, you have two options: add a USB card or add a USB hub. Adding a USB card makes sense if you have an unused 32-bit PCI slot or PCI Express x1 slot. These cards can provide up to four external USB 2.0 ports, along with an additional internal USB 2.0 port that supports front-mounted USB ports in a drive-bay mounted hub. For notebook computers that need more USB ports, an external hub is a better idea. However, you should make sure the external hub has its own power supply (a so-called 'self-powered' hub) and meets USB 2.0 standards.
USB Traps to Avoid
Avoid USB 1.1 cards and hubs unless you need extra USB ports only for low-speed devices like keyboards, mice, and game ports. Other USB devices, such as USB flash drives, printers, card readers, scanners, and hard disks need USB 2.0 support. USB 1.1 runs at either 1.5Mbps (low-speed) or 12Mbps (full-speed), while USB 2.0 supports both USB 1.1 speeds and USB 2.0's 480Mbps speed. USB 2.0 is also called Hi-speed USB. Self-powered USB hubs provide only 100mA of power per port, which is not enough for USB powered hard disk drives, flash drives or many other devices. Some of these devices can be damaged if they are plugged into a USB port without enough power.