A good portable hard drive is as handy as a pocket on a shirt. You can use one to back up your PC, carry important files with you on the road, store music and movies without clogging the hard drive on your PC, and more. In fact, there are countless other applications for portable drives, simply because you can never have enough storage. And that goes double when your boot drive is a smallish SSD.
Sure, cloud storage is one alternative to carrying a mechanism with you, but you need to have Internet access to use it (not always possible when you're traveling), and storing files in the cloud isn't always practical when you're dealing with large files or large collections of files.
Before you shop for a portable hard drive, however, you should know that very few of them provide data redundancy, meaning they don't duplicate the data they store. If a file becomes corrupted, you might lose that information forever. So don't use a portable hard drive to store irreplaceable information unless you have a duplicate copy stored somewhere else — on another hard drive in your computer, on a second portable hard drive, in the cloud, or on a network-attached storage device.
Now that we've established how useful a portable hard drive can be, let us show you how to choose the right portable hard drive for your needs. Performance and the features listed below the chart are the factors we take into consideration.
Factors you should consider
If you're buying a portable hard drive for a PC, buy one that's pre-formatted NTFS. Macs use the HTFS+ file system, so manufacturers sometimes offer a different SKU for each platform (or they might provide a pre-loaded NTFS driver for Mac users). If the drive you want is available formatted only HTFS+, you'll need to take the time to reformat it.
A platter-based portable hard drive will typically deliver more capacity at a lower cost-per-gigabyte than one based on a solid-state drive, but it will also be slower and more susceptible to damage if it's dropped. SSDs aren't impervious to shocks, but they don't have any moving parts.
USB 3.0 is the ideal portable hard-drive interface for PC users. It's ubiquitous on new PCs, and it's backward-compatible with USB 2.0 on older models.
Thunderbolt is the fastest hard-drive interface, and it's very popular on the Mac platform. Oddly enough, despite being an Intel technology, Thunderbolt ports are rare on the PC front — especially on laptops.
Firewire (aka IEEE 1394) is fast, too, but it's another interface that was more popular with the Mac community than with PC users — and it's on the way out because Thunderbolt is faster.
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