Everything you need to know before buying an external hard drive

Storing absolutely everything on your PC can be handy if you have space to accommodate it all, but even if you don't slow your Windows installation down to a halt, you'll be running the risk of losing everything stored on the PC if you do not back up. The easiest (and most affordable) way of backing things up on your PC and hosting media files on the go is an external hard drive. This can come in the form of a traditional mechanical hard disk drive (HDD) or a new solid state drive (SSD).

The choice may appear to be straightforward but there are a number of things you should consider before buying an external drive.

Cloud vs HDD


OneDrive Windows 10 Mobile (Image credit: Windows Central)

To save money, you could simply rely on OneDrive or similar services to store all your files. But this means you'll be relying on Microsoft to not only keep your files safe and secured from the outside world, but also an internet connection should you wish to access said files on a device that hasn't been synchronized. And it's also a pain sometimes to synchronize things across on a less reliable connection.

An external drive, on the other hand, allows for the quick and painless transfer of files. It keeps the process streamlined with little to fail, aside from the drive itself and perhaps the USB cable. There's also the case of cost and available space. You'll often need to fork out a specific amount per month for cloud storage, which could increase over time should you require additional capacity. With a physical drive, you only pay for the device itself.


3.5-inch HDD

Hard Drives (Image credit: Windows Central)

HDD storage is made up of magnetic tape and has mechanical parts inside. These bulky units (3.5-inch models) were traditionally used in PCs before SSD technology came along. 2.5-inch drives are smaller and more compact for use in laptops but offer less performance. These drives as a whole aren't as durable as flash-based counterparts but are significantly more affordable.

SSD is flash storage and has no moving parts whatsoever. This removes a layer of potential fault, being the motor in a mechanical drive. As a result are faster and use less power. Thanks to the lack of moving parts in SSDs, it's also possible to move them about while they transfer data to and from a PC without causing damage.

HDD vs SSD: Which should you have?

How big is too big?


SSD (Image credit: Windows Central)

When it comes to numbers, this depends largely on what you need to store on an external drive. The good thing about having physical drives as opposed to services is you can always purchase more and create a small collection (or part with more funds for even larger capacity). For thousands of images, a few home movies, some music, and documents, you could get away with anything between 100-500GB.

That said, there's no real harm in going too big. Pick up a 1TB (1,000GB) drive and you'll have more than enough space for the future.


Seagate SSD

Best External Hard Drives (Image credit: Seagate)

Depending on how much money you have to spend on an external drive (and whether you pick up an internal unit and an enclosure or pre-built unit), there are various factors and features that alter:

  • Speed — This not only relates to the type of interface (USB 2, USB 3, eSATA) but also rotation speeds in mechanical HDDs. Cheaper HDDs are 5200rpm, while more powerful 7200rpm drives will set you back a little more. SSDs are unaffected and vary depending on employed flash memory/technology.
  • Security — If you go for ready-to-use external drives, you'll have many options to choose from. Some will offer a basic storage experience, while others pack in additional security measures like encryption, as well as software suites and more.
  • Durability — Should you require an external drive that can withstand a tumble (or few), you'll need to opt for an offering that sports a rugged design and durable build to offer enhanced physical protection.

Which external drive is best?

Now you have a rough idea what you will need to consider when looking at external drives, which is the best on the market? It's a good question and lucky for you we've got you covered with our external drive buyer's guide:

Best external hard drives

Updated May 21, 2018: We updated this guide with more deals and suggestions for the best external HDD.

Rich Edmonds
Senior Editor, PC Build

Rich Edmonds was formerly a Senior Editor of PC hardware at Windows Central, covering everything related to PC components and NAS. He's been involved in technology for more than a decade and knows a thing or two about the magic inside a PC chassis. You can follow him on Twitter at @RichEdmonds.