The Synology DiskStation DS218+ is the best two-bay home NAS for most people. It typically sells for less than $350 (diskless) as of this writing, its read and write speeds are the fastest of any NAS we tested, and it includes a modern Intel Celeron processor, hardware-level encryption, and a flexible and easy-to-understand interface with a wide variety of third-party apps. The DS218+ supports media playback through its own apps or Plex Media Server, supports RAID 1 drive mirroring, alerts you to drive failure, has three USB ports (including one on the front), and supports all the features Wirecutter readers have asked about, such as the FTP protocol, VPN server capabilities, IP cameras, UPS compatibility, and SSDs.

The DS218+ had the best performance of the six NAS units we tested in 2017 and 2018, with unencrypted write speeds between 97 MB/s and 109 MB/s.

Most NAS devices in this price range use slower ARM-based processors from Realtek, Alpine, or Marvell, or older-generation Celeron processors. Some still ship with 1 GB of RAM or less. The DS218+ has a modern dual-core 2.0 GHz Intel Celeron processor and 2 GB of RAM, which you can expand to 6 GB. Our runner-up, the QNAP TS-251B uses the same Celeron processor and 2 GB of RAM, but the DS218+’s CPU is faster than the processor in nearly every other NAS currently available in this price range, and you’ll notice that speed difference when copying lots of files or performing multiple backups simultaneously. The Linux-based DiskStation Manager (DSM) software isn’t complicated; if you’ve used a Windows or Mac computer, you’ll be able to find your way around DSM and figure out how it works pretty quickly.

The DS218+ had the best performance of the six NAS units we tested in 2017 and 2018, with unencrypted write speeds between 97 MB/s and 109 MB/s. (You won’t see much higher speeds from another NAS unless you’re using 10 Gigabit Ethernet or link aggregation, because these speeds are right at the limit of Gigabit Ethernet when you take encoding into account.)

The QNAP TS-251B uses the same Celeron CPU, and its performance was similar to the DS218+ during side-by-side tests, though the DS218+ was just a bit faster than the TS-251B when dealing with lots of small files. Both handily beat the TS-231P2, the WD My Cloud Home Duo, and the Apollo Cloud 2 Duo in small-file write speeds. The playing field was much more level when we tested using our folder containing two large files: The DS218+ was in a dead heat with the TS-251B in our large-file write tests, and the differences between most models we tested, aside from the Apollo Cloud 2, Duo were minimal.

Aside from the beefier processor in this model, the DS218+ (as well as all other current Synology NAS devices) uses a different default file system than others, called Btrfs (most other NAS models, including offerings from QNAP, use the ext4 file system). The file system shouldn’t have a huge effect on the file-transfer speeds, but it does introduce some features to Synology NAS units that other models don’t have, such as snapshots, which can protect folders from accidental deletion by making copies of shared folders periodically. Btrfs also features near-instant server-side copying, data integrity checks, and metadata mirroring, which supposedly helps with data recovery in the case of hard-drive damage. Most NAS owners won’t notice the differences between the two. If you do prefer ext4 for any reason, you can set up the DS218+ to use that file system instead of Btrfs when you create a volume.

You can quickly find and install new applications in Package Center. Screenshot: Thorin Klosowski

The interface in DiskStation Manager offers an overlay for system health as well as easy access to all the settings you need. Screenshot: Thorin Klosowski

You get quick access to every package you install with DSM’s drop-down menu. Screenshot: Thorin Klosowski

You can quickly find and install new applications in Package Center. Screenshot: Thorin Klosowski

The interface in DiskStation Manager offers an overlay for system health as well as easy access to all the settings you need. Screenshot: Thorin Klosowski 1 of 3

The DS218+ doesn’t support volume encryption to securely lock your entire drive, unlike the QNAP TS-251B, but you can encrypt individual shared folders. Even with the DS218+’s hardware encryption acceleration, you’ll still see a ding to read-and-write performance with encryption turned on. In our tests, file transfer in encrypted folders was around 60 percent of the speed of transfer in non-encrypted folders. That hardware encryption acceleration also didn’t help with SMB in-flight encryption at all, which slowed the file-transfer process to around 50 percent of the speed of unencrypted transfers. In-flight encryption protects your files during the transfer process, so it’s not something you need to worry about if you’re on your home network the whole time.

The DS218+’s interface, DiskStation Manager, is one of the most user-friendly operating systems on any NAS device. DSM has a toolbar on the top where you can access the main menu, notifications, and login options, search for files, and check on system health. Below that toolbar, you have a desktop where you can access Package Center (a store of sorts filled with add-on software), the file browser, the control panel (which includes all your settings), and a support area offering video tutorials, FAQs, and more. Synology has a demo version of the operating system available online; it’s worth checking out before you make your purchase.

Like most of the NAS operating systems we tested, the DSM interface includes a pop-out dashboard widget that gives an overview of the NAS’s drive health, as well as its processor and memory usage. You can customize the dashboard to include storage, connected users, and more. DSM also includes handy features for novices. For example, if you click on the File Services tab in the DSM control panel, it displays the key command you’ll need to access the file share on your PC (“DS218plus”) or Mac (“smb://DS218plus”). While these commands may be familiar to veteran systems administrators, new users or anyone who has forgotten the server name will welcome the embedded tip.

DSM has an optional cloud service called Cloud Station Server that allows you to access your files remotely. If you don’t want to connect to any cloud service, you can still access your NAS remotely through a virtual private network (VPN) hosted on the NAS itself or Dynamic DNS with port forwarding, but for most people Cloud Station Server is much simpler. DSM also includes Cloud Station ShareSync, which allows you to use your NAS to sync files across devices, similar to a service like Dropbox.

There’s also the confusingly named Cloud Sync package, which allows you to sync or back up specific folders or your entire NAS to various cloud platforms, such as Backblaze, Google Drive, Amazon, and Dropbox, which makes creating redundant off-site backups very easy. You can set those backups to happen on a schedule and optionally encrypt them before you upload them to another service.

DSM packs in numerous security measures. In the main menu you’ll find a security adviser that alerts you to malware, improper network configurations, out-of-date applications, weak passwords, and any systemwide configuration issues, though you will have to log in to the DSM interface regularly to see its advice. It supports HTTPS for remote access, TLS or SSL secure connections, and two-factor authentication.

For better or worse, instead of having one big app with tons of features, Synology takes a piecemeal approach to its mobile apps. DS Audio, DS File, DS Photo, DS Cloud, and DS Video are for accessing media. DS Finder is for monitoring the stats on your NAS, DS Get is for managing downloads, and DS Cam is for managing IP cameras. There’s also VPNPlus if you’re using the VPN server functions, DS Note if you use Synology’s notes app, and MailPlus if you use your NAS as an email server. All of Synology’s apps are available for Android and iOS, and they’re on a par with those of Synology’s biggest competitor, QNAP. Both companies’ mobile apps are best in class among NAS devices—no other NAS provider comes close.

Like most NAS boxes, the DS218+ supports multimedia streaming through Synology’s own apps, DLNA/UPnP, and iTunes. In our tests, the DS218+ didn’t take long to scan a music and video library and make the files available across a Wi-Fi network on various computers, TVs, game consoles, and phones.

The DS218+ supports on-the-fly hardware transcoding, supposedly all the way to 4K video. It does this using its own Video Station and DS File apps. If you prefer to use Plex, you will not have access to the hardware transcoding features, since Plex’s transcoding is CPU-bound and NAS devices in this price range just don’t have the horsepower to do that. With Synology’s apps, we were able to play several 1080p MKV files on various devices over 802.11ac Wi-Fi without issue, but when we tried the same with three different 4K movie trailers, they were all unwatchable due to stuttering. We also had issues with any 4K video using the DTS audio codec, in which no sound would play. Some formats, such as M4V, wouldn’t play at all. Files that didn’t require any transcoding, like MP4 files, played flawlessly on all devices. On-the-fly transcoding is dependent on the file format, the various codecs, and the device you’re watching the transcoding file on, so your mileage will vary here.

Still, even though Synology advertises the DS218+ as being capable of all kinds of transcoding, you’ll want to use a more powerful computer than the DS218+ (or any other NAS in this price range) if you’re serious about on-the-fly media transcoding. We recommend transcoding your video files ahead of time if you plan on using your NAS as a media server. You can do this with the Offline Transcoding feature in Video Station, though unfortunately you need to manually choose individual videos to convert. If you’re looking for an automated option, QNAP’s software allows you to set up a specific folder that the NAS monitors; the NAS then transcodes any files you drop in.

Power-saving features won’t work if you enable any media server functions, because the NAS needs to be available all the time.

In our tests, the DS218+’s data-protection features worked as advertised. With the DS218+ running, we pulled the drive out of the second bay and the NAS beeped at us until we acknowledged a drive-failure notification. We also received an email notification at the address we’d set up previously. Logging in to DSM, we found another notification as well as instructions for how to rebuild the drive array in the Storage Manager once we replaced it.

The front of the DS218+ features a removable plate that hides away the drive bays, as well as LED indicators for general status, network connectivity, and the status of each drive. You can adjust the LED brightness or set it up on a schedule so the lights dim at night. The DS218+ has three USB 3.0 ports. It also has an eSATA port so you can expand the NAS with external drives using one of Synology’s compatible expansion units. Like every NAS we considered for this guide, the DS218+ has two drive bays. Unlike other options, the drive bays are tool-less, so you don’t need a screwdriver to install a drive.

A USB Copy button sits on the front of the DS218+, but before you can use it you need to tell the NAS what the button should do when you press it. For example, you can set it up so that when you connect a thumb drive you’ve stored photos on, pressing the button will copy the entire contents of that drive over to a specific folder. Or you can set it to export, say, only video files from a specific folder. It takes a little effort to get the button working how you want, but Synology’s guide should help you configure the feature. While QNAP models often have a front USB port, most other NAS boxes do not, so it’s nice to see on this Synology unit.

When it came to power consumption, the DS218+ consumed between 19 and 23 watts during file copy, slightly better than the QNAP TS-251A and TS-231P2. This Synology NAS used about 6 watts while in power-saving mode, compared with the QNAP models’ 10 watts. Power-saving features won’t work if you enable any media server functions, because the NAS needs to be available all the time; you have to disable media servers and a handful of other similar services, such as cloud access and the mail server, if you want the power-saving mode to work. You can also turn the DS218+ on and off according to a schedule, and it supports Wake-on-LAN and multiple fan-speed modes, the latter of which can help reduce the overall noise of the DS218+. No NAS is completely quiet, but to our ears the DS218+ was less noticeable than the QNAP TS-251A or TS-231P2.

You can add wireless capabilities to the DS218+ with a Wi-Fi dongle. This unit also supports more than 5,000 different IP cameras and has special configuration settings for uninterruptible power supplies. The DS218+ comes with a two-year warranty, and Synology offers various support options, including tutorials, email support, and browser-based text chat.