External Hard Drives: A Buying Guide

External hard drives can extend your computer’s storage space and store valuable backups. There’s a lot to consider when shopping around for a new drive, so we wanted to make everything simple and easy to understand.

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Here is a shopping guide on what to look out for when buying an external hard drive.

  1. Type And Size

Hard drives come in two basic types: Hard Disk Drives (HDD) and Solid-State Drives (SSD). HDDs employ spinning magnetic disks to store data while SSDs use integrated circuits with no moving parts to store data. SSD provides high data transfer speed in comparison to conventional disks but they’re much more expensive per gigabyte of storage.

Hard drives usually come in 3.5 and 2.5 inch varieties. This measurement refers to the width of the drive. Smaller drives will be more portable while larger drives usually have more storage space, so keep these trade-offs in mind.

  1. Speed

The speed of an HDD depends on the Revolutions Per Minute (RPM) of the drive. The read and write speed improves as the RPM of the disk increases, so larger numbers are usually better. You’ll see 5400 RPM and 7200 RPM drives most commonly in today’s market.

Solid State Drives are much faster because of their lack of moving parts. Here is a great example of an SSD external hard drive from Samsung.

 It’ll transfer data at extreme speeds, but it costs a lot more than traditional drives.

  1. Connectivity

Make sure to check what type of connection your drive uses. Most drives will use either a USB 2.0 or USB 3.0 port for data transfer.

USB 3.0 cables are backwards compatable with USB 2.0 ports but it doesn’t work the other way around. Make sure that you’re getting the most out of your device with the right cables.

  1. Storage Capacity

One of the most basic questions to ask while purchasing an external drive is “How much storage space will I need?” External drives come in various storage capacities starting around 350GB and going up to  around 8 TB (Although that much storage is going to cost a ton of money).

There’s no need to over-purchase on hard drive space. 500 GB – 1 TB will be more than enough for most people who want to back up their music, pictures, and video content. Expect to pay more for higher capacity drives, obviously.

Consider how much storage space you really need. If you only want to backup 20 GB of photos, think about skipping a hard drive altogether and just find a USB thumb drive


  1. Portability

Mobility is another key factor. Think of when and where you’ll be using your hard drive. Portable drives exist for the worker on the go, but they’re not going to hold as much data. The Seagate Backup Plus Slim

 is a great portable drive option.

Desktop drives aren’t as portable but usually allow for much more storage space for backups and capacity extensions. Just don’t expect to lug them around in your backpack. The WD My Book

 comes in multiple storage capacities and works well as a desktop backup option.

  1. Security

Some drives come with built-in security features for people who deal with sensitive information. This usually comes through special software utilities that require a passcode to access the drive’s data. It’s good to know that your data is safe if you happen to misplace the drive.

If you really want security try the Apricorn Aegis Padlock

series of drives, but you’re going to pay extra for the peace of mind. They come with a built-in physical keypad, so you need to know the code to access the data within.


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About the Author
Divya Palaniappan is an engineer and an avid techie who considers information worthless unless verified. When she isn't wracking her brain over machines she loves spending time in her garden.

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