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10 things to consider when buying an external hard disk-based storage device

man working at desk using a laptop and external hard drive
(Image credit: Getty)

If you're looking for physical rather than cloud storage, then external storage devices are the ideal solution for your back up needs, whether you are an individual or a small business. And with the digital explosion of movies, films, photos, games, and applications, external storage is more vital than ever before.

The price of external hard disk drives has fallen sharply thanks to a highly competitive storage market which has forced manufacturers to come up with novel ways of "packaging" dumb hard drive into smarter, albeit more expensive, storage appliances.

In its simplest form, an external hard disk drive is nothing more than an enclosure with a bit of electronics glued in and an internal hard disk drive stuck to it. At the other hand of the spectrum, more elaborate models boast automated backup and networking features as well as redundancy functionalities.

There are umpteen storage devices available on the market meaning that everyone's needs can be catered for, so here's our list of 10 things to be considered when purchasing an external hard-disk based storage device.

1. Storage size

Unsurprisingly, the amount of storage needed is going to determined what solution you will choose; generally speaking hard disk based devices carry the best combination of price and storage capacity.

1TB external drives can cost as little as $50/£40; you would need more than 200 blank DVDs or more than 1200 blank CDs just to match the capacity of these drives.

The rule of thumb is to choose a hard disk drive that has twice the capacity you currently need; this should accommodate for future needs, especially when you bear in mind that upgrading an external storage device is not as easy as doing it for a desktop PC.

2. Size of the drive

If you are seldom going to move the external storage device, it makes sense to invest in an external desktop drive which is bulkier than a portable version but will provide with more storage capacity at any given price. 

If portability is your primary concern, see whether a large capacity USB flash drive could possibly answer your needs; a 500GB flash drive will cost around $70, whereas a portable hard drive with the same storage capacity will be about half that much.

flash drive used on an apple laptop

If portability is a priority then you may want to opt for a flash drive. (Image credit: Getty)

3. Drive connectivity

There are currently three major connections on the market – eSATA, USB and Firewire. USB 2.0, as well as its faster cousin USB 3.0, are by far the most prevalent versions and offer great transfer speeds as well as quasi-universal compatibility.

eSATA is the newest kid in town and offers improved performance and consumes less resources than USB. Firewire is often relegated to niche and high end platforms like content creation but offers the best performance of the three as well as superb compatibility with the Mac environment.

4. Your budget

External hard disk drives are slightly more expensive than their internal counterparts and your allocated budget will help you decide whether you should go for a desktop bound solution or for a more portable one. 

All in all, the cheapest external hard disk drive solution costs under $30/£30 while the most expensive 16TB external drives currently on the market is available for around $350/£330.

5. Drive speed

Storage devices using desktop based components are likely to be the quickest but only when matched with an equally capable interface; for even faster performance, some manufacturers like LaCie, even allow two hard disk drives to be configured in RAID-0 mode which should significantly boost performance.

6. Software


Software is often the main differentiator between the various external hard disk storage devices solutions on the market. A great software package can make up for average performance and enhance the overall user experience, especially when dealing with something like backup. 

Some applications offer the ability to automatically upload files to dedicated websites, rollback systems and file encryption on the fly. Others have build-in synchronisation functionality and enable you to use your favourite applications like Microsoft Excel or Word.

7. Warranty

Some manufacturers like Seagate offer up to five year warranty on their storage solutions which comes handy should one of them fail to boot; bear in mind though that no manufacturer will provide data recovery facilities in case of hard disk failure.

8. Platform

Where you use your storage device could also determine which solution would work out best for you; are you a laptop, remote worker? 

Then it might be preferable to get a USB flash drive or a portable hard disk drive solution, many of which do not need an external power source. Furthermore, if you are a Mac aficionados, purchasing a Firewire model makes more sense as it will provide you with more expandability.

9. Sturdiness

Storage devices based on traditional hard disk drives are by default fragile but some are more than others especially the bigger ones which are more likely to suffer damage when dropped down.

If you are likely to experience kicks and knocks as well as the occasional drops, then better grab a flash drive rather than a spinning hard drive.

10. Security

External Storage device vendors like Western Digital bundle two hard disk drives together in order to improve redundancy if one of the hard disk drives fail; likewise, Seagate has a welcomed "on the fly encryption" feature which should keep your files safe, away from prying eyes.

Related: lost data on a flash or hard drive, external or internal? Then read our guide to the best data recovery software.

Désiré has been musing and writing about technology during a career spanning four decades. He dabbled in website building and web hosting when DHTML and frames were en vogue and started writing about the impact of technology on society just before the start of the Y2K hysteria at the turn of the last millennium. Following an eight-year stint at ITProPortal.com where he discovered the joys of global tech-fests, Désiré now heads up TechRadar Pro. Previously he was a freelance technology journalist at Incisive Media, Breakthrough Publishing and Vnunet, and Business Magazine. He also launched and hosted the first Tech Radio Show on Radio Plus.

With contributions from