Which hard drive is right for you? Our hard drive buyers' guide

Choosing the right desktop drive can be a challenge. Not only is it difficult to tell one small grey box apart from all the other small grey boxes, but there are so many specs involved that spotting meaningful technical differences can become difficult.

By Liz Sunter April 30, 2018

So let’s simplify things. Your choice of drive really comes down to three factors: speed, capacity and redundancy. You also need to consider the connectivity of the drive – there’s no point opting for a superfast Thunderbolt 3.0 drive if your computer doesn’t have the right ports or adaptors, for example.

Keep reading for a quick breakdown of what you need to consider, what RAID6 actually means, and the speeds you can realistically expect to get over various connections. You can also download the full guide to get all the key info and compare different drive models.

Speed: how fast do you need your drive to be?

Your drive’s speed dictates how quickly it can transfer and receive data (its throughput). For traditional hard disk drives (HDDs), typical throughput is between 120 and 250MBps, although you can increase the speed of multiple drives by using them in a RAID configuration. HDDs are made of spinning magnetic disks, and the higher the RPM of these disks, the better – most spin at 7200RPM, but some spin at the slower 5400RPM.

SSD drives are a newer, more reliable technology (they use a silicon memory chip rather than spinning disks, so there are no moving parts to break). They are much faster than HDDs, however, they have significantly smaller capacities, and the cost per GB of SSD storage is higher than that of HDD storage.

Capacity: how much space do you need?

Single HDDs are now produced in capacities of up to 14TB, while SSDs have much smaller capacities. If you’re working with large files, such as 2K, 4K or RAW images, you will definitely need the high capacity of HDD, but its top speed of 250MBps will be nowhere near enough for you.

To get across the 250MB threshold, you’ll need multiple drives working together in a RAID configuration. In this configuration, work is split between the different drives to increase their overall performance. RAID is also an important part of your final consideration, redundancy…

Redundancy: how much protection does your data need?

Even the most reliable drives can, and do, fail. Redundancy is the name given to how much protection against failure you have, because you achieve it by saving extra, ‘redundant’ copies of your data to use as back up if one disk fails.

Multiple drives can be configured into a RAID (it stands for redundant array of independent disks) in order to improve performance and offer protection against data loss. Different levels of RAID (from 0 to 6) offer increasing levels of protection. As with all things, there is a trade-off, and the more redundant you make your drives the lower their capacity becomes. (Download our hard drive buyers' guide for more on how this works.)

Connectivity: what kind of cables are you using?

Your drive – be it HDD, SSD, RAID or standalone – isn’t much use if it can’t connect to your Mac or PC. It’s important to find a drive that has the same connections as your existing kit, and to remember that having the latest connection does not guarantee you’re getting the fastest possible drive. 

USB 3.1 Gen 1 is ubiquitous and is included on almost every drive. Theoretically, it gives you a bandwidth of up to 640MBps, but in practice this is limited by the speed of the disks in your drive. Bear in mind that a two disk RAID will take up virtually all the available bandwidth in a USB 3.0 connection, so if you’re using a drive with more than two disks, avoid connecting via USB.

USB 3.1 Gen 2 is the latest version of the USB standard, and offers up to 10Gbps of bandwidth - double that of the previous generation.

Thunderbolt 2 Thunderbolt was first introduced by Apple in 2010, with a second generation following in 2013 and pushing the potential bandwidth up to a potential 20Gbps, or up to 1350MBps in practice.

Thunderbolt 3 Theoretically has 40Gbps of bandwidth, with speeds up to 2700MBps in practice. Drives with USB-C connectors will operate on Thunderbolt 3 ports at roughly the speed on USB 3.1 Gen 1.

Need something more specialist?

Back in the day, eSATA and FireWire were popular alternatives to USB. However, thanks to the increased bandwidth offered by USB 3.0 and Thunderbolt, drives with these connections have all but died out. There are a few bravely hanging on, though, so just give us a call if you need someone to find you a drive with these legacy connections.

How can you get hold of these? 

You can see our full range of drives here on our website. We offer same day and next day delivery options, including timed deliveries (pre-noon or pre-10.30am). To see more details about the various drives available, download the full guide.