An external hard drive is the most common way to back up your computer. Anybody who’s ever had their hard drive crash and lost all of their data is typically interested in ensuring that it never happens again. This is why external backups to ensure data redundancy are a keystone of savvy computer use.

In addition to needing the drive itself, you should also look into a backup software program. Otherwise, you’ll need to do all your backups manually, and frequently, ergo inconveniently. There are two options that we recommend. The first is Apple’s “Time Machine” program that is built into Mac OS X 10.5 Leopard and Mac OS X 10.6 Snow Leopard. It works really well and will keep an hourly, ongoing backup of your entire computer. Time Machine is most effective if you have a computer that you keep in one place and always leave the external hard drive plugged in.

The other program that we recommend is Intego’s “Personal Backup” program. It costs about $70, but includes a lot more features than Apple’s Time Machine. Personal Backup will back up any specific files or folders you select, and it’ll back them up either at regularly scheduled times, or (and this is the best part) right when you plug the external hard drive into the Mac. I recommend Personal Backup if you travel a lot and will not have your computer plugged into the external hard drive for longer than necessary.

Besides keeping an ongoing computer backup on your external hard drive, you can also store files on it that you just don’t have space to keep on your internal hard drive. Particularly media, like music or videos, which takes up a lot of space but doesn’t necessarily need to be accessible at all times.

The best external hard drive brand (in our experience) is G-Tech. Other options include Western Digital, LaCie, and Verbatim drives. G-Tech’s G-Drives are about %15 more expensive but extremely durable, as well as having the aesthetic properties most similar to your Mac. Western Digitals and LaCies are less expensive but not as durable, since plastic is more heavily utilized in their construction. This also means that they’ll be somewhat less effective at dissipating excess heat buildup. The Verbatim is fairly durable, reasonably priced and not a complete eyesore. Any of these options is a viable way to back up your computer, but the G-Drives consistently prove themselves the most dependable.

G-Tech’s product comparison site

Western Digital’s products page

LaCie’s main webpage

Verbatim’s main products site

Apple also makes their own backup solution; they call it the Time Capsule (shown at right). This is a backup solution unlike any of these others, because the backup can occur wirelessly. For this additional feature, there’s a significantly higher initial cost to the consumer. The backup itself is also VERY slow over a wireless network, exponentially slower than any of the drives that are plugged directly in. So for desktops, it’s not the best option. Since the computer is always going to be sitting in the same place on a desk or table, why not buy a cheaper, plug-in external and leave it there too? The backups will be much faster, allowing for less of an interruption in your workflow. For laptops, the Time Capsule proves more useful. Certainly, it regularly will back up your entire computer over the wireless network, as long as it’s in range. It’s still much slower, but you don’t need to devote any effort to it. It can be a good solution if there are multiple laptops within a household, since it can be configured to back up each of them individually. The Time Capsule, irrespective of its backup capabilities, can also easily replace your current wireless router, so your wireless internet signal is coming from the same piece of hardware that your laptops all get backed up to.

A key point to remember is to ensure you get one that has a FireWire connection, not just a USB or USB 2.0 connection. There are two kinds of FireWire, 400 and 800. FW 800 is up to twice as fast as FW 400 but your old computer can’t use it. Your best bet is to get a hard drive that has ports (or cables) for both FW 400 and FW 800 so that you can one day use that hard drive with a newer computer and the fast speed. Some low-end Apple computers no longer have FireWire of any kind, so it’s always good if USB is also an option, even if it’s slower. The newer computers are phasing out FireWire 400, so going forward you will find it useful to have the FW 800 port too. Do not buy a hard drive that only has FireWire 800 or a hard drive that only has USB.

All three of those brands make travel sized hard drives (here we’re referring to the physical size of the piece, not that data capacity) that are about the size of a wallet. They also do not require a power cord. This is particularly good because if you travel and want to bring the hard drive with you since there’s one less cord to get in the way, and you can do backups as necessary completely from a laptop’s battery power. The external hard drive actually receives its power from the FireWire or USB cord connecting it to the computer. These are the options most suited for people using laptops/portables.

As for the data capacity of the drive, you will want to buy something in about the 1 TB range if it is going to be used with a stationary desktop computer. You could probably go as low as 500 GB or as high as 2 TB (equal to 2000 GB). Anywhere in that range will be good for your purposes. The larger the better because that means it will be useful for more years into the future as it will get full less quickly. If you are going to buy one of the small travel-sized drives you can get one in the 250 GB to 500 GB range.

You can purchase these external hard drives at any Apple Store or at Tekserve. Try to find a sales rep with some experience working with them. Leave a comment if you’d like a deeper analysis of a particular make/model/setup.