NAS drives are like cloud storage: you can access all your files from anywhere, both inside and outside of your home or office. You can use them to store and play your music and video collections, as well as documents and other files.

NAS drive buyer's guide

NAS stands for Network Attached Storage. It enables you to have a large amount of storage connected directly to your broadband router. This storage is therefore available to all your devices.

NAS drives are designed to be turned on permanently, which means you can have access to your music, movies, photos and documents at all times. Most have timers so you can set them to turn on and off during the hours you want.

One of the most popular reasons to buy an NAS drive is for media playback. Videos can be viewed on your TV, without having to connect a computer.

A NAS drive will use much less power than a regular PC, too, making it much cheaper to run. For ease of setup and ease of use, a dedicated NAS drive is hard to beat.

What capacity do I need?

The first requirement is capacity. You'll need one that has enough storage to meet your needs now and in the future. Plenty of NAS drives come with no disks at all - these are known as diskless or bare drives. The advantage is that you can choose the drives you want and how much capacity you need.

You can now get disks up to 10TB is size, though for you’ll be paying at least £400 or so for the privilege. 4TB disks are arguably the current sweet spot, at around £120.

Disks for NAS drives

When you choose your disks, look for ones that have been designed to work specifically with NAS boxes. NAS-optimised features include more secure construction providing more resistance to vibration, which makes a lot of sense for a drive that’s designed to be on the whole time. They also offer power management so they can adjust performance based on their temperature.

These drives also offer special features in firmware known by WD as TLER (Time-Limited Error Recovery) and by Samsung and Hitachi as command completion time limit (CCTL). This optimises the error correction for drives when they are installed in a RAID array (explained below) as is usually the case with NAS drives.

What is RAID?

RAID stands for redundant array of inexpensive disks. RAID can be quite complex but at a basic level you’ll want to use it primarily to provide redundancy so if a disk fails your data is still safe. Three of the most popular variants are RAID 1, 5 and 6.

Most NAS drives will offer at least two bays, which means that you can set them up as RAID 1. In this scenario the second drive is a mirror of the first, so if one drive fails completely all your data is safe on the other. You can then replace the faulty disk, and rebuild the RAID array.

RAID 5 requires at least three drives and offers parity data. That means a RAID 5 array can withstand a single drive failure without losing data or access to data. As data is ‘striped’ across three drives, reads are fast, but at the expensive of slower writes because of having to also write the parity data.

RAID 6 meanwhile requires four drives but offers both striped and dual parity, so two drives could fail and the RAID could still recover.

Whichever you choose however, don’t consider RAID to be your only backup of your data. If the box just dies, or if something catastrophic happens like a fire, you’ll still lose all your data. To mitigate this you'll want another external backup, preferably to the cloud.

Hot swap

Hot-swap capability enables you to take out or add a drive without having to power down first, which could be important if you’re running business applications off your NAS and want to maintain uptime.

Remote connectivity

Consider whether you’ll need remote access to the drive. Previously this required signing up to a third-party DNS service, but these days with most NAS drives you can just sign up for an account with the manufacturer as you set up the drive. Log into the account and they'll handle the connectivity to your box at home.

Transcoding

How powerful does your NAS’s processor need to be? The dedicated OSes that NAS drives run are lightweight, but a faster processor and more memory will enable features such as transcoding.

This means that any media files can be converted on the fly into a format that's playable by your TV or set-top box, so you don’t have to worry if it can't play the file as it exists on your NAS. 

Best NAS drives to buy in 2018

1. Synology DS218j

Synology DS218j
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 10 January 2018

With excellent performance, brilliant software and easy setup this entry-level NAS drive is another great buy from Synology.

Ok, it's not much different to the DS216j, but it's hard to improve on something already impressive. And at only around £20 more, it's certainly worth going for the 218j over the older model.

Read our Synology DS218j review.

2. QNAP TS-231P2

QNAP TS-231P2
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 15 January 2018

A small but remarkably powerful NAS box with buckets of functionality, scalability and value that demonstrates well how seriously QNAP now takes its NAS product range.

If the TS-231P2 is an example of where QNAP is heading, then the future for home and small-office NAS storage devices is a truly exciting one.

Read our QNAP TS-231P2 review.

3. Synology DiskStation DS418j

Synology DiskStation DS418j
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 11 September 2017

Synology wants to repeat the success of the DS416j without treading on the toes of other products in the range. For almost the same price the DS418j offers more CPU performance, RAM, more USB 3.0 ports, larger drives and volume sizes.

Read our Synology DiskStation DS418j review.

4. QNAP TS 251A

QNAP TS 251A
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 30 December 2016

The QNAP is an undoubtedly impressive NAS drive. There’s plenty of power for virtually all tasks, and H.265 aside it will handle anything you throw at it. The range of apps is very comprehensive and the interface is excellent. The downside is the lack of support for MKV from its native app, which will mean having to pay for Plex to play files on mobile devices. The unit was also noisier than we would have liked in operation and while it’s good value - it’s not cheap. If you’re willing to stretch to paying this much for a diskless system, the QNAP TS-251A is the best featured NAS drive at the price.

Read our QNAP TS 251A review.

5. Synology DS218

Synology DS218
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 1 February 2018

The fine irony of the DS218 is that seen in isolation it’s an excellent platform, but jammed between the DS218Play and the DS218+ leaves it little room for manoeuvre.

With QNAP now offering Dual-LAN for less money and RAM upgradability, the DS218 needed to be less expensive or be similarly enhanced.

The DS218 is a superb NAS enclosure but fails to outshine the DS218Play sufficiently to make it a no-brainer.

Read our Synology DS218 review.

6. Asustor AS1004T

Asustor AS1004T
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 27 December 2016

We like the Asustor AS1004T for its ease of installation, it's relatively quiet operation in normal use and its decent performance. It isn't fast enough for hardware transcoding though, so you’ll need native support for all your files on all your client devices.

Where it trumps the completion is that it offers a four-bay chassis where some offer only two. If storage rather than performance is the priority then, it's a great choice and while the ADM interface isn't as accomplished looking as some of its rivals it's got the apps you'll likely need.

Read our Asustor AS1004T review.

7. Drobo 5N2

Drobo 5N2
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 9 January 2018

It might be relatively expensive, but the flexible RAID system that can handle multiple drives of different size could be a major cost saving for many users. The performance, build quality and expanding app selection also makes the Drobo 5N2 a highly desirable solution.

 

Read our Drobo 5N2 review.

8. WD My Cloud Mirror 4TB

WD My Cloud Mirror 4TB
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 2 January 2017

When it comes to ease of use the WE My Cloud Mirror is hard to beat. Initial setup is very easy and even sorting our remote access is simple too. For sharing music, movies, photos and documents it works a treat and performance is fine. The downside is that you don’t get the huge range of apps that are available for other brands. However, if you prioritise ease of set up and ease of use the WD is worth looking at and with 4 TB of storage included for the price, it’s a great value option.

Read our WD My Cloud Mirror 4TB review.

9. WD My Cloud Home

WD My Cloud Home
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 20 December 2017

The design and styling of the hardware in the My Cloud Home is top-notch, with all its issues lying in the software components provided for it. The underlying platform is a solid one for which WD hardware engineers should be proud, and the software team needs to better support.


The My Cloud Home can provide DLNA storage to access with a smart TV or a personal cloud solution, but those that want more should consider Synology, QNAP or the higher-end WD My Cloud products.

Read our WD My Cloud Home review.

10. Netgear ReadyNAS RN212

Netgear ReadyNAS RN212
  • Rating: ratingsratingsratingsratingsratings
  • Reviewed on: 28 December 2016

The Netgear’s physical design is very impressive, but a few issues mean it lacks the appeal of drives we’ve tested from QNAP and Synology. In particular the interface for installing and using apps isn’t the best we’ve seen, nor is the range of choices.

Performance is good, but the ARM processor doesn’t quite have chops to handle 4K transcoding. It’s a good NAS, but only if you can find it cheaper than the competition.

Read our Netgear ReadyNAS RN212 review.