Buyer's Guide: Backup

Stop what you're doing. Imagine the display in front of you suddenly goes blank. Imagine you can't reboot your computer. Imagine all the data on your hard drive has now disappeared.

A frightening scenario, yes? But it's one that millions of computer users flirt with every day. And many of them do it without a backup of their data.

There are plenty of excuses for not backing up data. None of them, though, hold any real weight. Backups take up too much time. Backups are hard to set up. Backups require additional hardware that's expensive. All it takes is one hard disk crash, or even corruption of a few key files, to impress on you how thin those excuses are.

Moreover, improvements in backup technology and the plummeting price of hard disk storage have turned many of the old rationalizations for failing to add a backup component to your system or systems into myths. While initial backup times can be prolonged, subsequent backups can be drastically reduced through incremental backups and real-time synchronization. Improved software packages and software/hardware combinations have made set-and-forget backups easier than ever. And hard drives with massive capacities can be bought without draining your savings account.

Size Matters

When choosing a backup system, one of your first decisions will be whether to buy an internal or external hard drive. Internal drives cost less than external drives, and they can transfer data between the hard disk and computer faster. Two hard drives in a RAID 1 array are the quintessential form of automatic backup -- one drive is a mirror image of the other. However, internal drives require sweat equity to install, as well as some dexterity with tools. Of course, you can have someone else install the drive for you, but that could cost you more than you paid for the drive.

External drives are, by far, the most popular for backups. They're easy to set up. All you do is plug the drive into a port on your computer and you can perform basic storage functions. They're portable. You can move them from one computer to another or, in the case of "pocket" hard drives, take them on the road with you. Portability, however, can be a curse as well as a boon. Every month or so there's a story about a portable hard drive full of sensitive data misplaced by someone. If you intend to fully exploit the portable potential of your backup drive, it might be wise to have a second backup should the first one go AWOL.

After choosing between an external or internal drive, you'll want to pick a size. To some extent, a hard drive's capacity is tied to the size of its platters -- 3.5-inch hard disks can store more data than those with 2.5-inch or 1.8-inch platters. Drives with the larger disk size consume more power and are generally less portable.

While larger external drives need to be plugged into a wall outlet for their power, smaller drives--like Western Digital's Passport Elite line--can be powered through the cable that connects them to your computer. However, since all ports on a computer aren't created equal, some pocket drives have a special cable that occupies two ports so they can get adequate power to operate.

Drives with larger platters currently top out at about two terabytes (TB) and pocket drives at 500 or 640 gigabytes (GB). Those numbers are boosted by disk makers by incorporating more drives in a single housing. So you can find desktop devices with 4TB capacities and pocket drives with 1TB of storage. However, the smaller capacities are easier to find in the market.

Once you've decided on the capacity you want for your backup drive, you should shop around for one with the lowest cost per megabyte. When it comes to capacity, bigger is usually better--not only because it gives you more room to store stuff, but generally larger disk drives perform better. It's not uncommon, for instance, to see better performance from a 1.5TB hard disk with a speed of 7,200 rpm than a 500GB drive running at the same speed.

Whatever capacity you choose to meet your needs, you'll probably find a price to meet your budget. It's easy to add 1TB of backup capacity to your computer for around $100. That's enough for 750,000 MP3 music files or photos, or over 230 movies' worth of home video.

Choosing Interfaces

After choosing what you want to connect to your computer for your backups, you'll want to choose how you want to connect it. Common interfaces are eSATA, FireWire (a.k.a. IEEE 1394) and USB 2.0. eSATA is the fastest of the three, but only newer computers have eSATA ports built in to connect such drives out of the box.

There are two versions or speeds of FireWire; at 400Mbps and 800Mbps -- dubbed, naturally enough, FireWire 400 and 800 -- they bracket the 480Mbps of USB 2.0.

There are also some more exotic interfaces that you might run into when shopping for an external drive. There's wireless USB. It's relatively new and not commonly found on hard drives. There's iSCSI. It's usually used in professional-grade drives.

And there's USB 3.0. As with eSATA, it's easier to find USB 3.0 drives than computers they can plug into (at full speed, that is; USB 3.0 hardware works fine, albeit at USB 2.0 speeds, when connected to the latter type of port). But it does have a lot of promise, however, as its speed -- a theoretical bandwidth of 5Gbps or ten times that of USB 2.0 -- makes USB 3.0 a good choice for an external drive you can use at USB 2.0 speeds with your current PC and at blazing speeds with your next.

External drives can be purchased with multiple interfaces. Since a drive for backup purposes is usually attached to a single computer, a single interface will most likely meet your needs, unless you plan to use the same drive with two or more PCs (a Mac with FireWire and a PC with USB 2.0, for example).