There are many reasons why you might want to have a storage system in your home. It's an easy way to backup files from your computer and phone, and World Backup Day is coming up soon. You can use it to cut the cord and stream video around the world using Plex. Maybe you want to store surveillance camera footage to keep your family safe. And a NAS device can be used for more than just storing files by running virtualization such as Docker containers. There's also the benefit of having full control of your data instead of relying on cloud services that may change their terms of service or worse, suffer a breach.

If any of these options sound like something you want to pursue, then you owe it to yourself to take a look at the Synology DS1522+, a five drive solution that can act as the central hub in your home while allowing you to access your files while you're away.


The DS1522+ looks like any other Synology NAS device we've reviewed, ranging from two-bay models to the six-bay model, with this version sporting five bays.

Synology packs the most powerful hardware in the + line, but the DS1522+ is a bit of a mixed bag. The company moved away from Intel processes and is instead using a dual-core AMD Ryzen R1600 running at 2.6 Ghz base and 3.1 Ghz turbo and supports AES-NI for encryption. This processor is better than the predecessors with one important distinction: It does not support hardware transcoding. That means it's not a great solution for a media server.

From a memory perspective, the Synology DS1522+ comes standard with 8 GB of DDR4 ECC SODIMM and is expandable to 32GB (2x16GB SODIMMS).

Picture of the back of the Synology DS1522 showing two 92mm fans USB ports and RJ45 jacks

There's are two 92mm system fan in the back to keep the DS1522+ cool, and it's very quiet so it won't be distracting in a home office setting.

Picture of the front of the Synology DS1522 showing 5 bays power button and lights

There's the obvious five drive bays, allowing up to 90 TB of storage space (5x18 drives). The DS1522+ also allows for up to two five-bay expansion devices via the eSATA ports, which gives a maximum of 270 TB of space if you wanted to live on the edge with just a bunch of disks (JBOD), although running that much storage without any redundancy is probably not the smartest thing to do so I'd recommend using RAID-6 for extra protection. If you want to ensure using only supported devices, you can review Synology's compatibility page, but using non-supported drives doesn't bring up any errors on this line of devices.

CPU AMD Ryzen R1600, dual core, 64-bit, 2.6 GHz with AES-NI encryption
Memory 8 GB, maximum 32 GB (16 GB x 2)
Disk Capacity 90 TB (18 TB drive x 5) without expansion, 270 TB (90 TB + 90 TB + 90 TB) with 2 DX517 expansions (hot swappable)
Network 4 RJ-45 1 GbE with link aggregation/failover
USB Ports 2x 3.2 Gen 1
NVMe Slots 2
Size (H/W/D) 6.54 in x 9.06 in x 8.78 in / 166 mm x 230 mm x 223 mm
Weight 5.95 lbs / 2.7 kg
Price $700 / €800

From a connectivity perspective, there are four Gigabit Ethernet ports on the back that can be aggregated into one to improve performance. Note that you can't increase your throughput from a single stream, but rather the aggregation can be used as either failover in case a switch port dies, or can be used to improve bandwidth on multiple streams.

Picture of back of Synology DS1522 showing exposed PCIe port eSATA and USB

The DS1522+ also has a PCIe expansion slot in the back that can be opened to install an optional 10 GbE card. The card, called the E10G22-T1-Mini, uses a standard RJ45 connection. The performance of this feature is tested below.

The DS1522+ has two USB 3.2 Gen 1 ports, one on the front and one on the back. If you're confused about the new USB naming standards, you aren't alone, but can read more about it here. The "copy to NAS" button has been removed from Synology devices for awhile, but I don't think is something most people were actively using.

Picture of the bottom of the Synology DS1522 showing two exposed NVMe slots

There are two NVMe slots on the bottom of the DS1522+. When I reviewed the DS720+, I recommended against using an NVMe drive as cache in a home setup because there was simply no performance benefit. However, according to Synology, you can now use the cache to store all of the Btrfs metadata, which should speed up file access and searching. Another update is the ability to add and remove the cache without impacting availability to the volume, a welcome addition, albeit one that probably doesn't get used too frequently. Unfortunately I didn't have an NVMe drive to test this with yet, but hope to in the future.

Picture of the back of the Synology DS1522 showing four Ethernet ports and the PCIe card installed

You can secure the DS720+ with a Kensington lock if you're concerned about the physical security of the device. Finally, the drives themselves can be locked with an included key.

The Synology DS1522+ is priced at $700 in the United States, and €800 in Europe.

Hardware Installation

If you're looking for something that's plug and play, you can't go wrong with Synology devices. To get them up and running, simply connect the disks to the sleds, and plug them into the front drive bays. Then plug in an Ethernet cable, plug the power cable in, and then turn the device on. The system will boot up, obtain an address via DHCP, and you can connect to begin the installation process.

If you're installing the optional E10G22-T1-Mini PCIe card that provides 10 GbE functionality, then you simply unscrew the back plate, plug the card in, and screw the card into place. The whole process takes only a few minutes. The PCIe card costs roughly $149 from Amazon at the time of this review.

Initial Setup and Configuration

I had drives laying around from my review of the DS1618+, and when I put them into the DS1522+, DSM7 identified the data on the drives and asked if I wanted to retain it.

The process for migrating the data was straight forward and my only two choices were whether I wanted to retain the system configuration and if I wanted to upgrade to the latest version of DSM. After making the selections, I was warned that data on one of the drives would be deleted, but I continued anyway.

Unfortunately when the process completed, the storage pool was giving errors and although the system was working fine, the storage piece was not. I ended up having to reinstall everything from scratch. That said, it's possible the issue was related to a failing drive because several days after doing a complete reinstall, one of the drives failed. I'll show you the process of replacing a failed disk in the "Replacing Drives" section, below.

Installing DSM 7 is a very streamlined process. You first have to select a username for the administrator account and select a password, followed by selecting whether you want automatic or manual upgrades of DSM. Next, decide if you want to link your NAS to a Synology online account and whether you want the NAS device accessible via the Internet. After that, the system does its thing and after a few minutes, you have a fully functioning NAS device, just waiting for you to configure the storage.

One interesting thing did occur when trying to set the admin password: Although the installation claimed that the password I selected was "strong," when I clicked the "Next" button, I was given an error message that indicated the password strength requirements included mixed case and numbers. I guess it wasn't as "strong" as the GUI indicated.

After you have the base installation of DSM in place, it's time to setup a storage pool. DSM again makes this extremely easy with a guided wizard so that in a few clicks, you'll have a pool up and running. Start with deciding what RAID type you want depending on your fault tolerance requirements. SHR and SHR2 give you single or double disk redundancy, respectively, and are the preferred choices. You can also select the older RAID-5 and RAID-6 which work in a similar manner but have less flexibility. Finally, RAID-10 (full mirroring) and RAID 0 (no mirroring) are also options, depending on your needs.

If you select drives that are not officially on the Synology compatibility list, you're given a warning but, unlike their enterprise models, this is the only time you'll see the system complain. This whole compatibility list has been a source of contention with Synology users for awhile but so far, the company hasn't forced it upon smaller home environments. It's on this page that the system also notified me that two of my drives had bad sectors, a precursor to the failure I mentioned earlier.

Finally, you allocate how much space you want to give the pool (normally you'll click the "max" button), select the filesystem type (brtfs is recommended), and let the system start building the storage pool.

Replacing Drives

Mechanical hard drives are far cheaper per gigabyte than their SSD counterparts, but the downside is that they're more prone to failure, which is why it's recommended to protect your data using SHR or SHR2. If you have that level of redundency in place, then DSM makes recovering from a failure as easy as clicking a few buttons and replacing the drive, and the interface clearly shows you what drive has failed.

The process, captured in the screenshots above, requires you to click on the bad drive (highlighted in red when failed), then under Action, click on Deactivate Drive. Once the drive is offline, you're given a notification that it's safe to replace the disk and after you insert it into the drive bay, a popup prompts you to repair. Wait for the pool to rebalance, and the process is done. It honestly couldn't be any simpler.


The easiest interface in the world doesn't really matter if the device doesn't perform. I'm happy to report that this is not a concern; the DS1522+ has great performance when copying both large and small files to and from the device.

As with all of my NAS reviews, in order to test performance and bypass the PC as much as possible, I used OSFMount to create a 4GB RAM disk and then used Robocopy to test throughput between my desktop and the DS1522+. The volume on the NAS was created as SHR using the Btrfs filesystem. In addition to the above method, I also used CrystalDiskMark 7.0.0 x64 to run some tests to confirm that the performance matched what I was seeing with the manual tests, which they did.

For my test, I created five separate shared folders, each one configured slightly differently in order to see how certain features would impact performance. The tests included:

  • A regular filesystem
  • A filesystem with integrity enabled
  • A filesystem with integrity and compression enabled
  • A filesystem with encryption enabled
  • A filesystem with encryption and integrity enabled

Screenshot showing six shared folders in Synology DSM

DSM applies an icon on the folders to help you identify which ones are running encryption (padlock) and which ones have compression enabled (two arrows pointing at each other). There's no icon showing whether filesystem integrity has been enabled or not.

Screenshot of performance benchmark

The results of both my Robocopy and the CrystalDisk were similar, and the overall performance was great, with large file transfers practically maxing out the gigabit Ethernet connection, and smaller file transfers doing almost equally well.

Screenshot of performance benchmark

For those interested in input/output instructions per section (IOPS), the Synology DS1522+ performed similar across all volumes as well.

Sequential 1MiB (Q=  8, T= 1):   118.489 MB/s [    113.0 IOPS] 
Sequential 1MiB (Q=  1, T= 1):   114.503 MB/s [    109.2 IOPS] 
    Random 4KiB (Q= 32, T=16):   115.531 MB/s [  28205.8 IOPS] 
    Random 4KiB (Q=  1, T= 1):    16.436 MB/s [   4012.7 IOPS] 

Sequential 1MiB (Q=  8, T= 1):   118.476 MB/s [    113.0 IOPS] 
Sequential 1MiB (Q=  1, T= 1):   111.562 MB/s [    106.4 IOPS] 
    Random 4KiB (Q= 32, T=16):   115.069 MB/s [  28093.0 IOPS] 
    Random 4KiB (Q=  1, T= 1):    16.090 MB/s [   3928.2 IOPS] 

Next up, I ran the same tests, only using the E10G22-T1-Mini PCIe card that provides 10 GbE functionality. That's where things got interesting, showing the true performance capabilities of the DS1522+.

Screenshot showing CrystalDiskMark 10 gbe performance

As expected, CrystalDiskMark showed the NAS device capable of extremely high read speeds. However it also shows the limitations of write speeds, as they're roughly 40% lower than the maximum read speeds. Even still, it far surpasses the speeds we saw with the gigabit Ethernet connection, hitting peaks of 728 MBps.

Screenshot showing CrystalDiskMark 10 gbe performance

As expected, the number of IOPS is also much higher when using the 10 GbE connection. Below are the stats from the Encryption and Integrity run:

Sequential 1MiB (Q=  8, T= 1):   723.010 MB/s [    689.5 IOPS] 
Sequential 1MiB (Q=  1, T= 1):   711.336 MB/s [    678.4 IOPS] 
    Random 4KiB (Q= 32, T=16):   358.247 MB/s [  87462.6 IOPS] 
    Random 4KiB (Q=  1, T= 1):    45.407 MB/s [  11085.7 IOPS] 

Sequential 1MiB (Q=  8, T= 1):   377.242 MB/s [    359.8 IOPS] 
Sequential 1MiB (Q=  1, T= 1):   348.949 MB/s [    332.8 IOPS] 
    Random 4KiB (Q= 32, T=16):   111.701 MB/s [  27270.8 IOPS] 
    Random 4KiB (Q=  1, T= 1):    34.806 MB/s [   8497.6 IOPS] 

Running at 10 Gbps means setting up your Shared Folders requires a little more thought to the function versus performance. For example, while you can hit 728 MBps with only integrity configured, once you turn compression on, that maximum speed drops to 487 MBps. While this is still much faster than a standard gigabit Ethernet link, it's still significantly slower than without compression enabled.

The only other time I've reviewed a 10 GbE NAS was the Thecus N7710-G, back in 2015. Back then, I was impressed by the 235 MB/s performance, as it was the fastest I had seen at the time. In 2023, it's clear that the Thecus was being held back by a combination of hard drives, CPU, and memory, since the Synology DS 1522+ is capable of hitting 728 Mbps.

Having said that, although performance is great for file transfers and will be very good for most applications, since the DS1522+ uses an AMD Ryzen R1600, and that CPU does not have an embedded GPU, you will not get very good performance when transcoding. You also will be unable to use the Plex hardware acceleration functionality. If you're only streaming native resolution, this will be a non-issue and Plex will run great, but if you like to transcode (for example, down-res a 1080p movie to 480p when streaming outside your home to save mobile bandwidth), then you might want to consider a different device with hardware transcoding functionality.


For many people, the Synology DS1522+ (or any NAS) is used primarily as a file repository for backups or easy access to documents, but a modern device can do so much more. There are a number of pre-made packages that can be installed from the Synology Package Center that extend the functionality of the DS1522+. For example, Synology Photos can be used to replace Google Photos, Surveillance Station can be used to record CCTV in your house or business, or a media tool like Plex can be installed to share video to devices around the world, as we showed in a previous article. The ability to use Docker containers or virtual machines opens up options to run practically anything on the NAS device.


The DS1522+ builds upon what the previous generations have provided and improves them. I feel like five drive bays is a sweet spot for people who want the protection from double drive failure that SHR2 offers, while still maintaining a large capacity: fFive 16 TB hard drives would give you 48 TB of usable storage and would be able to withstand two drive failures. The ability to triple that space with the optional DX517 expansion modules means you'll be able to grow even more if needed.

Picture of the Synology 10GbE card on a box

The 10 GbE PCIe card is a nice addition for those who need the extra throughput. For streaming, it's not really needed, but if you're editing photos or video on a desktop, you'll welcome the faster speed, assuming your network supports it.

That said, Synology really dropped the ball by removing hardware transcoding from its platform, since hosting a Plex server or something similar is a very common use case amongst NAS owners. It will still work great if you're streaming everything in native resolutions, but you might overload things going from 4k down to 480p to watch on the go.

Ultimately, deciding on a NAS device comes to down to your individual requirements. For example, more bays is not always better, especially once you factor in the price of hard drives. Those with more modest storage requirements may be better off with a 2-bay device. The user experience is great with both QNAP and Synology, but both are a little different, so if you're undecided, I highly recommend checking out both the Synology demo site and the QNAP demo site to see which you prefer. Finally, many tinkerers would prefer building their own server which is definitely a cheaper option, but without the polish of a dedicated NAS.

If you have no need to transcode video on the fly and want a five bay NAS device, then the DS1522+ is a great solution for every other use case and I can highly recommend it.

Synology DS1522+
Great performance with Gigabit and 10 Gigabit Ethernet connections DSM 7 is easy to setup and use for beginners and experts alike Reasonably priced for a five bay NAS device
No hardware transcoding on the Ryzen CPU Cost versus building your own server


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