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.
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).
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!
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.
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.
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.
Comments are closed on this article
Loraine_Burchell
May 25, 2011 at 10:19am
This seems a smart shopping guide indeed! I mean it's not very difficult to buy devices using USB ports but sometimes some advice is useful. Nowadays though, you can find these devices anywhere and they are pretty cheap because there is a big competition out there. When I was in vacation last year and I was trying to chose one of the Shanghai restaurants to have dinner I was shocked to see so many computer stores in that area.
HeartBurnKid
November 27, 2007 at 10:31am
One thing that's incorrect about your guide is that there are self-powered USB 1.1 hubs floating around out there. They're still slow as molasses, but they will at least power your devices.
I've got one on my rig; makes for a cheap and handy place to plug in devices that don't need a ton of bandwidth, like keyboards, mice, gamepads, etc.
Marcus_Soperus
November 28, 2007 at 2:52pm
Thanks for pointing out that USB 1.1 hubs still have a place on some PCs. In this article, I was referring specifically to the "Black Friday" mini-hub offerings that lack AC adapters, but I appreciate the clarification that some USB 1.1 hubs do include AC adapters (I still have a USB 1.1 hub hanging around my shop).
My main gripe with the big-box stores pushing USB 1.1 hubs at this late date is that unwary consumers may buy them for use with all of their USB devices - and then wonder why their USB 2.0 devices are so slow.
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It's amazing how illogical a business built on binary logic can be.
RPGgddss
November 25, 2007 at 9:53am
I never knew there was so much to think about when buying USB stuff!
Jondi "RPGgddss" Schmitt
Your friendly neighborhood techie Tupperware lady
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