NAS: the appliance of storage science
NAS appliances offer a handy way to expand your storage across your network, so are they a better choice than external disks?
Investing in a new hard disk is an easy way to expand your storage, but it has its limitations. The obvious one is that only one computer gets the benefit: giving your desktop system a handy terabyte of breathing space doesn’t do anything for the overloaded SSD in your laptop. And while today’s external drives tend to be light and compact, they’re still an extra box to take up desk space or to carry around with you.
As an alternative, it’s worth considering a standalone NAS appliance, which connects to your router and can offer both shared and private storage to every device on your network. NAS systems offer several advantages over directly connected drives, but there are also some caveats to be aware of.
■ Speed
Since NAS appliances operate over your home network, performance will depend on the connection between your client machine and the router. If you’re loading and saving large files over a legacy Wi-Fi link, you’ll be lucky to get transfer rates of around 30MB/sec, while a strong Wi-Fi 6 connection can boost that to around 60MB/sec. With a wired Gigabit Ethernet connection speeds might top 100MB/sec.
That’s fine for everyday documents and photos, but it’s not exactly speedy: some of the SSDs in this month’s Labs are literally 30 times faster. If you frequently work with big files, that performance differential could have a big impact. Then again, drive speed is most important when running Windows and other software, and you can’t do that from network storage anyway.
“The mechanical disks used in a NAS appliance aren’t just cheaper than SSDs – they also come in much bigger capacities”
■ Price
A NAS solution is almost always more expensive than buying a single SSD. A basic two-bay home appliance, such as the TerraMaster F2-210 ( pcpro.link/324f2) will cost you around £150, while a four-bay model such as the Synology DiskStation DS420j ( pcpro.link/324ds) will set you back around £270. And these are unpopulated prices: you’ll need to factor in the price of the actual disks on top of that.
The good news, sort of, is that the speed limitations of a home NAS mean you might as well use low-cost mechanical disks, rather than costly SSDs. A pair of NAS-certified 4TB disks can be had for £90 each, so your overall outlay per gigabyte needn’t be wildly different, compared to buying a single high-speed M.2 drive.
There are also a few pre-populated, selfcontained options, such as WD’s My Cloud Home Duo ( pcpro.link/324my). However, while these may seem like good value, they lack the full versatility and expandability of a “real” NAS appliance.
■ Capacity
The mechanical disks used in a NAS appliance aren’t just cheaper than SSDs – they also come in much bigger capacities. Right now you can buy single drives in 8TB, 12TB and even 18TB capacities, while desktop SSDs rarely go above 2TB.
So if, for example, you’re a keen videographer looking for a huge data tank to store archives of 4K or 8K footage, a NAS might be the most practical option – subject to the performance limitations. If you buy an appliance with more bays than you need, you also have the option of easily and economically extending your storage at a later point by simply installing additional disks.
■ Reliability
All NAS appliances offer at least two drive bays. If you want, you can install a pair of disks in these and combine them into a single large volume. This isn’t recommended, though: the real point of multiple bays is for RAID mirroring or paritybased fault tolerance. With this enabled, if one of your disks breaks down, your data can be fully recovered from the remaining drives. If you rely on a single SSD for storage, one hardware failure means all the data on that volume is gone for good.
It’s important to note, however, that redundancy isn’t a replacement for backup. RAID won’t help you if you accidentally overwrite a file, or if your documents are locked up by ransomware. NAS folders need backing up just like any other folder.
Nor is RAID exclusively a NAS feature: you can install multiple
drives in a desktop PC and combine them into an array, and it’s possible to get desktop RAID enclosures that connect directly to your computer via USB or Thunderbolt, combining some of the benefits of NAS with the performance of a local disk.
■ Convenience
The more computers you have in your household, the more it makes sense to invest in a NAS appliance.
It’s the perfect way to make your files available on any device, without proliferating duplicate copies that waste space and cause confusion. If need be, you can use account management to restrict what certain clients or individuals can access.
Many NAS systems support remote access, so when you’re travelling you can get at your files over the internet. And sync services allow you to configure Dropbox-style local folders and synchronise them across all enrolled computers.
■ Features
Fundamentally, the difference between a bare SSD and a NAS appliance is that the former is a resource for your computer, whereas the latter is a computer in its own right. In addition to looking after your files, a NAS can serve as a streaming hub for your music, photos and videos, a central virus-scanning portal, a host for your websites and databases and more. Many models even support virtualisation and containers, allowing you to turn your NAS into a complete, always-on application server.
If you want to take that route, though, look closely at the hardware specifications when choosing a NAS. Low-cost home appliances often use lightweight ARM processors and may ship with only 1GB of RAM, which is a recipe for sluggish performance.