What Is an External Hard Drive?

An external hard drive is a storage device physically separate from a computer. It usually connects over USB and may have its own added power source. They are generally larger and have more capacity than a USB flash drive, though the most expensive USB flash drives rival the storage of some external hard drives.

Factors to Consider When Buying an External Hard Drive

Every external hard drive can handle the basic task of storing some files, but there’s a variety of storage capacities, technologies, and connection options available. This can make your choice complicated. Keep these key points in mind.

PriceStorage technologyStorage capacityConnection typePower requirements

How Much Should an External Hard Drive Cost?

External hard disk drives remain affordable at higher capacities. It’s less expensive to buy a single external hard disk drive in the capacity you need than it is to buy multiple, smaller drives. External solid state drives are different. Price rises quickly with capacity: 16TB drives are often $3,000. It’s less expensive to buy multiple, smaller drives than it is to buy a single, larger drive.

What Storage Technology Should an External Hard Drive Use?

External hard drives use one of two storage technologies: a hard disk or solid-state storage. Hard disks are literal metal disks inside an enclosure. They spin when data needs to be written or retrieved. This makes them more fragile, slower, and louder when in use. There’s also a limit to how small they can become, as the smallest hard disks in use are 2.5 inches across. These problems are offset by low pricing: hard disks have the highest storage capacity for your money. Solid state drives are, well, solid. They don’t have moving parts and instead store data by shuffling electrons. This makes them more reliable, as the drive lacks spinning components that can break. They’re silent and often smaller than external drives with a hard disk. The solid-state chips they use are more expensive, however, so expect to pay more per gigabyte.

How Much Storage Capacity Should an External Hard Drive Have?

The simple answer, of course, is “as much as you need.” Yet this can might be difficult to determine if the files you want to store are strung across multiple folders on your PC. Prices fluctuate constantly in this market, but we suggest starting at a 1 terabyte (1TB) model as they offer quite a bit of room and are usually only a couple of dollars more than a smaller capacity drive. A larger drive might be necessary if you want to store dozens of hours of 4K video, thousands of DSLR photos, super-sized images, or vector-based arts. If you are working with those kinds of files, you likely know how big the files are and how many you need to store.

What Connection Type Should an External Hard Drive Use?

Most external drives connect over one of the USB standards available today. Older models connect using USB Type-A, and USB Type-B, while newer ones will use USB Type-C. Almost all external drives come with their own cable, so the only variable is which port your computer has. That’s why it’s worth knowing the types of USB ports on your computer. Even if the cable fits into the port on your computer, you may notice disappointing performance if you plug an external drive into a slow USB port. If this is true of your computer, consider sticking to a slower and less expensive external hard drive, since you won’t see the benefit of newer, faster models. USB Type-C is the newest connection and offers quick data speeds as well as power all over one cable. USB Type-C is physically different from the older USB-A connection. You can buy a USB-C to USB-A adapter if your computer lacks USB-C, but the USB Type-A port might not be able to provide power to the drive (if the drive doesn’t come with its own power supply). There’s one last connection to mention: Thunderbolt. Thunderbolt 3 and Thunderbolt 4 are physically compatible with USB-C but often quicker, with a mandatory bandwidth of 40 gigabytes per second. Thunderbolt isn’t used by most external drives because USB is usually fast enough, but you may encounter Thunderbolt on high-end external drives. You’ll need a Thunderbolt 3 port on your PC to make the most of this connection.

What Power Requirements Do External Hard Drives Have?

Most modern external hard drives don’t require external power. They instead are powered entirely over USB, which draws power from your computer. That means you don’t need to use a power brick. This isn’t always true, however. Large external hard disk drives are the most likely to need external power. This is also true of older external drives produced before USB 3 and Thunderbolt were common. An external hard drive that requires its own power isn’t really meant to be moved around a lot even if it is, technically, able to be moved about. Only buy an external drive with a power brick if you’ll rarely if ever, need to move it.

Who Should Buy An External Hard Drive?

An external hard drive will appeal to anyone who needs more storage and doesn’t want to (or can’t) upgrade a computer’s internal hard drive. Internal hard drive upgrades are often less expensive, but more difficult, and many laptops don’t support upgrades at all.

What to Do After You Buy An External Hard Drive

External hard drives are plug-and-play, meaning they don’t require additional driver or software installation to work. Connect it to the best available USB (or Thunderbolt, if supported) port. Your computer should recognize the drive almost immediately. If it doesn’t, use the links below to prepare the drive.

More Tips for Buying an External Hard Drive

External hard drives are relatively simple devices with few hidden features or quirks. You may want to consider a drive’s warranty or promised longevity. You’ll see warranties between one and ten years, depending on the manufacturer. A longer warranty period hints at better reliability, so consider a drive with a long warranty if you’re concerned about data loss. The most important tip is this: keep an eye on the price. Because external hard drives differ so little between brands and features, it’s almost always worth shopping for the lowest price.