By John Swenson
Installing new hardware in a computer is typically not a joyful, heart-warming experience. The potential pitfalls are numerous: missing drivers, PC cases you can’t figure out how to pry open, the difficulty of finding just the right type of memory, video card, or other compatible device.
That’s why adding an external hard drive is such a breath of fresh air. Usually, all you have to do is connect the power cord (some small, portable hard drives don’t even need that), plug one end of the USB cable into the drive and the other end into a USB port on your computer, turn on the drive, and wait for Windows to install it.
That’s it. Even if the drive comes with software from the manufacturer, the drive will usually work fine without it (although I recommend installing the software anyway). Windows can automatically find and install drivers for most models.
External hard drives have become so good, so dependable, and so easy to install that they’ve become one of the most popular of all computer peripherals. You should be able to shop for any external hard drive in your price range, plug it in, and have it work.
To delve into the details, keep reading.
Most external hard drives include a USB 2.0 connection. That’s because almost all PCs—even mobile PCs—have at least two USB 2.0 ports (also called “high-speed” USB ports) where you can plug in various devices. Many desktop PCs come with four, six or even more of these USB ports.
There’s a good chance your PC has at least one unused USB port available, but you should check before you buy an external hard drive. If you’re out of ports, you’ll need an add-in card with more USB ports, or an external USB hub.
An external USB hub plugs into an existing USB port on your computer and acts like an extension plug to create more ports. You should avoid plugging an external hard drive into a USB hub, however, because the drive might need more power than some hubs deliver in order to operate at its maximum speed. Plug an external hard drive directly into a USB port in your PC.
Some external hard drives also come with Firewire (IEEE 1394) or eSATA (external Serial ATA) ports—the newest and fastest type of port. Many PCs lack an eSATA port. If it’s important to you to have the fastest external hard drive possible, you can install an inexpensive card that adds eSATA ports to a desktop PC (mobile PCs have no room for add-in cards like this).
An external hard drive with an eSATA connection can pass data back and forth between the computer more than six times faster than a hard drive with a USB 2.0 connection and almost four times faster than drives with the speediest Firewire connection. Despite that speed advantage, most people find USB drives fast enough.
One of the most popular reasons for buying an external hard drive is to use it for backup. External drives often include backup software, to make it easier for you to backup your files. These programs vary widely in quality, so read an online review first if you are selecting a drive for its backup software.
Other leading uses of external hard drives include:
Adding more storage space after your main hard drive starts to fill up.
Adding extra space for digital photos, music, video—or all three.
Adding storage space to a mobile PC.
Shuttling a lot of files between two locations, such as home and work (especially if you use a desktop PC you can't take with you like a mobile PC).
External hard drives aren’t new—they’ve been around since the late 1990s. But they didn’t gain popularity until high-speed USB or Firewire ports became standard equipment on computers, giving people an easier and more reliable way to connect external drives.
External hard drives are getting so fast and inexpensive that many people buy them to avoid cracking open their PC cases and installing a second internal drive. Internal hard drives are still less expensive than external hard drives of the same size, but not by much.
If you’ve used only older, external hard drives, the improvements might surprise you. Today’s external drives don’t look much different, but they store a lot more, cost a lot less, and perform better than drives from a few years ago.
In 2003, I bought a 160 gigabyte (GB) hard drive from one of the biggest hard drive manufacturers. At the time, it was state-of-the-art and fairly expensive. But the drive was always hot and noisy. So noisy, in fact, that I ran a long cable into my closet and connected it there, to muffle its constant low whine. And so hot that I could feel heat radiating off the drive from a foot away.
Compare that to the 500GB external hard drive I recently bought. It cost less than half the price of the earlier drive and has three times as much space. I can’t even hear the new drive when it wakes up and starts spinning. And I can hardly detect any heat even when I place my hand directly on the drive. It’s noticeably faster, too.
How much difference is there between external hard drives from different manufacturers? Not a lot, in my experience. But that’s not to say that there are no quality differences—there are.
I’m willing to spend more for a drive with a good dependability record. No one wants to risk losing precious data. If you’re concerned about quality and reliability, look for reviews and user comments before you buy.
If you examine the manufacturer specifications of different hard drives with identical storage capacity, they often appear identical. To set their products apart, manufacturers have begun adding designer touches to their external hard drives, giving them sleek lines, glowing lights, and unusual enclosures. Some drives sit on their side to take up less desk space.
Hard drive capacities are getting so big that I hesitate to even discuss size. Any recommendation about what size drive to buy today is likely to be obsolete in six months.
Most external hard drives are still measured in gigabytes, although more and more high-end models can store 1-2 terabytes (1,000-2,000 gigabytes). Most of these terabyte-sized drives today contain two or more disks, in a bigger-than-normal enclosure.
As I write this, the largest external hard drives in a slim, conventional-size enclosure store 1 terabyte (TB) of data. The vast majority of external hard drives sold still hold 750GB, 500GB, or less.
While shopping for external hard drives, you’re likely to run across some products that look like external hard drives but are called NAS (network-attached storage) devices.
NAS devices are similar to external hard drives: both contain hard drives, store files, and sit outside of your computer. But you typically plug a NAS device into your network, not directly into a PC.
Because NAS devices are connected to a network, not to only one PC, you can access them from multiple PCs on the network. If you want to save files from more than one PC to the same storage device, or share files among multiple PCs, then it might be good to invest in a NAS device instead of an external hard drive.
Because of these extra capabilities, however, NAS devices are usually more expensive than external hard drives with the same storage capacity. So if cost is a deciding factor, stick with external hard drives.
Most external hard drives operate at the same speed as most internal hard drives, spinning at 7,200 revolutions per minute. Portable hard drives are the exception.
Portable hard drives trade speed for size and convenience. These small drives usually spin at a slower speed—5,200 RPM—and don’t plug into AC power; instead, they take all their power from the USB port on the computer they’re plugged into (typically a mobile PC). They store less data, too, so you get less storage space for your money than with a standard, non-portable drive.
The tiniest portable drives are so-called “pocket drives” that are as small as an MP3 player you can slip into a shirt pocket.
Many mobile PC users are happy to accept these size-versus-speed tradeoffs because portable external hard drives are ideal for use with mobile PCs. You can take a portable drive with you when you travel and use one to safeguard data (make copies of the files on your laptop), or store extra files you don’t have room for on your mobile PC.
Mobile PC storage space is often tight. You can’t add a second hard drive inside a mobile PC, and it’s a huge chore to upgrade the primary hard drive. To add a larger hard drive inside a laptop, you’d have to remove the original drive, install a new internal drive in its place, reinstall Windows and all your programs, and then painstakingly restore all your files and settings from a backup.
Compare that to plugging an external portable hard drive into a USB port and it’s no contest.
With hard drives growing bigger and bigger, it’s easier than ever to become a digital pack rat. Soon we all might be able to keep collecting pictures, music and other digital stuff forever, without the need to ever delete one precious file (or even non-precious files).
So the next time you start running low on space, just grab another external hard drive, plug it in, and keep going. You never know when you might need one of those old files.
About the author
John Swenson is a writer on the Windows team at Microsoft. In his nine years at Microsoft, he's done everything from digging up developer news for MSDN to interviewing technical leaders around the company. Previously, he was a business and technology reporter for newspapers and trade magazines.
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