What's With the Y-Cable on Some Portable USB Hard Disk Drives?

Portable USB hard disk drives are based on power-sipping 2.5-inch disk drive mechanisms, so, unlike their bulkier (and higher-capacity) 3.5-inch USB drive siblings, they can be powered off the USB bus. Ideally, a single USB port should do the job. However, because some systems don't provide a full 500mA of power per USB port and some hard disks require more power (up to 1000mA in some cases) to spin up, many portable drives include (or offer as an option) a two-port USB cable. In most cases, the power/data USB connector on the cable does the job, but on a system with low-powered USB ports, plug in the second power-only connector, and you're in business. See the review at right of a Seagate 40GB USB hard disk to learn more about this method.

Alternatives to Borrowing an Additional USB Port

Some drives, such as Verbatim's SmartDisk product line, include a piggyback cable that plugs into a PS/2 mouse or keyboard port to provide additional power for a bus-powered hard disk. Some 2.5-inch hard disk enclosures also use this method. If your system has unused PS/2 ports and a shortage of USB ports, you might prefer one of these to a portable hard drive that uses a USB Y-cable (the method used by Seagate, Maxtor, and Hitachi, and offered as an option by Western Digital via its online store).

USB 1.1, the Standard That Will Not Die...but Why?

Believe it or not, the original 12Mbps USB 1.1 standard is still alive and well, at least in the external hub market. The only USB devices that won't care if you plug them into a USB 1.1 or USB 2.0 port are input devices such as mice and keyboards. If you plug any of today's USB hard disks, printers, flash drives, card readers, scanners, and so forth into a USB 1.1 port, you will slow them down from the 480Mbps transfer rate enjoyed by Hi-Speed USB (aka USB 2.0) devices to USB 1.1's feeble 12Mbps transfer rate. You'll get very sleepy waiting for your picture to print or files to transfer at 12Mbps!

Who's Selling USB 1.1 Hubs?

Big-box electronics retailer Circuit City is selling a Belkin USB 1.1 hub for $5.99 today, and Staples is offering a $9.98 Targus USB 1.1 mini hub this weekend. - but no amount of savings can make up for stifling the performance of your USB 2.0 devices by plugging them into a USB 1.1 hub. To make matters worse, these hubs don't include external power supplies, so they can't support devices that require more than 100mA per port.

USB 1.1 devices like these are gifts that keep on giving...frustration.

Making Sure You Don't Get Suckered by a USB 1.1 Device

There are other types of USB 1.1 devices stores are anxious to unload this holiday season. To make sure you don't get suckered, make sure hubs, card readers, and other USB devices are identified as supporting Hi-Speed USB or USB 2.0. A device identified as "USB" is probably a slooow USB 1.1 device.

Buy Smart - and Keep Your Receipts in Case You Goofed

So, as you review the Friday morning's doorbuster deals you scarfed up and prepare to go out again for more holiday shopping deals, keep an eye on USB device speeds and power requirements. Don't feel bad if you picked up a device that won't work the way you intended. After all, that's what receipts and return lines are for.