Synology now sells everything from a two-bay box for a home office to a petabyte-scale array that feeds a GPU cluster. Most buyers shop by model number and end up with the wrong one. Here is a clearer way to think about it, range by range, and problem by problem.
Most people who buy the wrong Synology do not buy a bad product. They buy a good product aimed at someone else’s problem. They pick a model because a forum thread mentioned it, or because it was the cheapest unit with enough bays, and only later discover it cannot do high availability, or its processor will not transcode, or it was never designed for the workload they bought it for. The range has grown a lot, and the naming does not make this easier: a string like RS4826xs+ tells you everything if you can read it and nothing if you cannot.
This guide is written to fix that. It explains what each Synology family is actually for, how to decode the model names, and then, the part that matters most, how to choose based on the problem you are solving rather than the badge on the front. As Malta’s only Synology Platinum Partner, we specify these systems for businesses here every week, and the single most useful thing we do is stop people buying by spec sheet and start them buying by requirement.
Start with the problem, not the product
Storage decisions go wrong when they start with the hardware. The right order is the reverse. Before any model number enters the conversation, four questions decide almost everything else: Where does it live, on a desk or in a rack? What is the job, file serving, virtual machines, backup, surveillance or AI? Can it ever go offline, or does the service have to survive a hardware failure? And how fast does the storage itself need to be, measured not in capacity but in how many things hit it at once? Answer those four honestly and the range narrows to one or two families before you have looked at a single price.
How to read a Synology model number
Synology names are not random once you know the pattern. Almost every model breaks into three parts: a letter prefix that tells you the family, a number, and an optional suffix that tells you the tier.
The prefix tells you the family
The first letters are the most important thing on the box. DS is DiskStation, a desktop unit. RS is RackStation, the same idea built to bolt into a server rack. FS is FlashStation, all-flash and built for speed. SA is the enterprise line that uses SAS drives and can run as a high-availability pair. HD is high-density, designed to pack the most drives into the least rack space. UC is a Unified Controller, a dual-controller unit aimed at block storage. PAS is the newest enterprise line, an active-active all-NVMe array. GS is a further enterprise line arriving alongside it. And DP is the DataProtection family, the ActiveProtect backup appliances, which are a different kind of device covered on its own below.
The number tells you size and generation
After the prefix, the digits loosely encode the number of drive bays and the model year. In RS4826xs+, the leading figures point to a large bay count and the trailing pair, here 26, indicates a 2026-generation model. You do not need to memorise the scheme; you only need to know that a bigger number generally means more bays and a newer unit, and that two units in the same family differ mostly by scale.
The suffix tells you the tier
The letters on the end set the performance class. A bare model is the standard line. + (Plus) denotes the small-business tier with a faster processor and more memory. xs and xs+ are the high-performance enterprise tiers. J is the value line for light home use, and Play historically marked units with hardware transcoding for media. So DS224+ reads as a 2-bay, 2024, Plus-tier desktop, while RS4826xs+ reads as a large-bay, 2026, enterprise rackmount. Same grammar, very different machines.
Expansion units use their own letters
Add-on enclosures that extend a main unit follow a parallel scheme: DX for desktop expansion, RX for rack expansion, FX for flash expansion, and PAX for the PAS line. These hold drives but no brain of their own; they attach to a host unit to grow its capacity. Worth knowing so you do not mistake an expansion shelf for a standalone NAS.
The Synology families, one by one
With the naming decoded, here is what each family is genuinely for and who tends to buy it. This is the reference section: skim to the family that matches where your unit will live and what it will do.
DiskStation (DS): the desktop default
The DS line is what most people mean when they say “a Synology.” It is a desktop box, typically two to eight bays, that sits on a shelf or under a desk and serves files, runs backups, hosts a private cloud and handles light virtualisation or surveillance. The Plus-tier models (DS224+, DS923+ and similar) are the workhorses for small offices and serious home users. If your need is shared storage for a team, a backup target, or a private alternative to a cloud drive, and it does not have to live in a rack, a DiskStation is almost always the starting point.
RackStation (RS): the same idea, rack-mounted
RackStation units are functionally the rackmount counterparts to DiskStations, sized to bolt into a standard 19-inch rack in a server room or comms cabinet. They scale from compact short-depth units up to large xs+ enterprise boxes. You move from DS to RS not because you need different software but because you need rack form factor, redundant power supplies on the higher tiers, and the density and serviceability a rack environment expects. Most Maltese businesses with a proper server room and more than a handful of staff land here. The 2026 cycle brings a wave of new RS models such as the RS4826xs+ and RS3626 series.
FlashStation (FS): all-flash for speed, not bulk
FlashStation units are all-flash: every bay holds an SSD, and there is no slow hard-disk tier. That makes them the right tool when the constraint is latency rather than capacity, for example databases, virtual-machine datastores, or shared media catalogues full of small random reads that defeat a hybrid unit’s SSD cache. The trade-off is honest and worth stating: flash costs several times more per terabyte than hard disks, a gap that has widened during the 2026 NAND price surge, so FlashStations are about consistent speed in a sensible capacity envelope, not the cheapest way to store bulk archive. The compact FS200T brings this all-flash design down to a near-silent desktop unit for studios and small offices, where the larger FS units are rackmount.
SA series: enterprise SAS and high availability
The SA line is Synology’s enterprise tier built around SAS drives and, crucially, the option to run two units as a high-availability cluster. In that configuration one controller is active and a second stays in lockstep as a standby, taking over automatically if the active unit fails. This is for organisations that cannot tolerate extended downtime from a single hardware fault. It is worth being precise about what this does and does not do: high availability keeps a service running through a hardware failure, but it faithfully mirrors data, so a deletion or a ransomware encryption is copied to the standby too. Availability and backup are different problems, a distinction we walk through in our high-availability and air-gapped backup case study.
HD series: maximum density
The HD line, such as the HD6500, exists to pack the largest number of drives into the least rack space. These are high-bay-count units for organisations storing very large volumes of data, such as media archives, surveillance estates and backup repositories, where the priority is terabytes per rack unit. If your problem is “we have an enormous and growing amount of data and limited rack space,” this is the family that addresses it directly.
UC series: dual-controller block storage
The Unified Controller line provides dual-controller storage aimed at block-level workloads, presenting capacity over iSCSI and similar protocols to servers that want a SAN rather than a file share. It sits between the file-serving NAS families and the top enterprise arrays, for environments that specifically need shared block storage with controller redundancy without stepping all the way up to the NVMe class.
PAS series: active-active, all-NVMe, top of the range
The PAS line, led by the PAS7700, is the newest and highest tier, arriving in 2026. Two things set it apart from everything above it. Its controllers run active-active, so both serve data at once and either can carry the full load on failover with no service interruption, a step beyond the SA line’s active-passive design. And it is all-NVMe with block storage over NVMe-over-Fabrics and a direct-to-GPU data path, which makes it the family Synology positions for AI training pipelines, large-scale virtualisation and high-transaction databases. This is infrastructure for a data centre, not shared storage for an office, and it is priced and specified accordingly.
GS series: further enterprise storage
Alongside PAS, Synology is expanding its enterprise portfolio with the GS line in 2026, broadening the options at the top end for large-scale and performance-critical storage. As these models reach the market we will cover where they fit relative to the SA, UC and PAS families; for now the takeaway is simply that the enterprise tier is widening, and the right choice at that level is best made with a partner rather than from a spec sheet.
DP series and ActiveProtect: a different kind of device
The DataProtection (DP) family is the one that surprises people, because it is not a NAS in the usual sense. These are the ActiveProtect appliances, turn-key backup devices that ship pre-populated with drives and run a dedicated operating system called ActiveProtect Manager rather than DSM. They are designed to back up large fleets of machines, servers, virtual machines, PCs and Microsoft 365, from a single console, with immutability and data isolation built in to resist ransomware. The line ranges from small tabletop units like the DP320 up to rackmount appliances such as the DP7400 that can oversee thousands of servers and many sites at once. If your problem is specifically “back up everything we run, centrally and safely,” the DP family is purpose-built for it where a general NAS is a more manual fit.
Now choose by the problem you are solving
With the families clear, here is the more useful lens: start from what you are trying to do and let it point to the right range. These map closely to the scenarios Synology itself organises its platform around.Shared files and a private cloud for a team
For everyday file serving, collaboration and a private alternative to a public cloud drive, a Plus-tier DiskStation covers most small offices, and a RackStation does the same job where a rack and redundant power are expected. DSM’s Synology Drive handles desktop and mobile sync, anywhere access and multi-site file synchronisation. Capacity and user count, not exotic features, drive the choice here.Running virtual machines
Virtualisation is latency-sensitive and random by nature, which favours flash. A handful of VMs runs comfortably on a Plus-tier unit with an SSD cache; a serious virtualisation estate belongs on a FlashStation or, at scale and where downtime is unacceptable, on the active-active PAS line. The deciding factors are how many VMs hit the storage at once and whether a storage outage can be tolerated.Ransomware resilience and immutability
Defending against ransomware is less about a specific model and more about features available across the DSM range on Btrfs: immutable WriteOnce snapshots that even a compromised administrator cannot delete for their retention window, combined with an air-gapped or offsite copy. For dedicated, fleet-wide protection with isolation built in, the DP / ActiveProtect appliances are purpose-made. We cover the practical design in our air-gapped backup case study.Compliance and long-term data retention
Where GDPR, NIS2 or sector rules require defensible retention, the requirements are versioning, immutability, tested restores and audit trails, all of which DSM provides on a suitably specified RackStation or enterprise unit. The model matters less than the configuration. We work through what compliance actually demands, as opposed to what a brochure claims, in our compliance backup case study.High-throughput media and creative work
Video and design teams need sustained throughput and many concurrent streams, which points to a FlashStation for the working set, often paired with a high-capacity RackStation or HD unit for the archive. The network matters as much as the drives here, a theme we explore in our video editing NAS case study.AI and GPU-driven workloads
Feeding a GPU cluster is the problem the PAS line was built for. Ordinary file-share storage cannot deliver data fast enough to keep expensive accelerators busy; NVMe-over-Fabrics and a direct-to-GPU path can. If you are standing up AI training infrastructure, this is the family to look at, and the one least suited to being chosen without engineering input.Centralised backup for everything you run
If the goal is to back up servers, virtual machines, endpoints and Microsoft 365 across one or many sites from a single pane of glass, the DP / ActiveProtect appliances are the direct answer. For smaller setups, DSM’s own Active Backup for Business does much of the same job on a standard DiskStation or RackStation. The dividing line is fleet size and how much you want managed for you out of the box.Where buyers most often go wrong
A few mistakes recur often enough to be worth naming. The first is buying on capacity alone and discovering the unit cannot do high availability, or its processor cannot keep up with the workload. The second is assuming a high-availability pair removes the need for a backup; it does not, because it mirrors corruption as faithfully as it mirrors good data. The third is over-buying, putting an enterprise array behind a workload a Plus-tier desktop would have served for a fraction of the cost, usually because a bigger number felt safer. And the fourth is under-buying on the network: an all-flash unit on a single gigabit link is a fast engine behind a closed gate. The right unit is the one matched to the problem, and sometimes that is a smaller, cheaper box than the one a buyer walks in expecting.How this works with a partner in Malta
The range is wide enough that the most valuable step is not picking a model but framing the problem correctly, and that is the part we do with clients here. As Malta’s Synology Platinum Partner, Sirap specifies these systems against your actual workload, designs the network and data-protection layers around them, and supports them locally rather than through a distant queue. For qualifying businesses, investment in storage and data protection can also align with Malta Enterprise schemes such as the Smart & Sustainable Investment Grant, which we can help structure. The goal is the same one this guide started with: the right Synology for your problem, chosen on purpose. Talk to Malta’s Synology Platinum Partner →Explore Synology by need
Use these guides to find the right Synology system for your use case:
- Which Synology enterprise appliance is right for you?
- Synology 2025 Plus-series desktop NAS guide
- High-availability and air-gapped backup
- Compliance backup and retention
- Synology NAS for video editing and media
- Why Sirap is a Synology Platinum Partner in Malta
Or go straight to a system: the all-NVMe PAS7700 and all-flash FlashStation FS200T for performance, the dual-controller SA3400D for high availability, the ActiveProtect DP7200 backup appliance, the RS2825RP+ rackmount or the DS1825+ desktop NAS. See the full backup and data storage hub.
Featured Products in this article
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Synology FlashStation FS200T Compact 6-bay All-Flash NAS
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Synology PAS7700 Active-Active NVMe Enterprise Storage
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Synology RackStation RS4826xs+ 12-Bay Rackmount NAS
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Synology RackStation RS3626xs+ 12-Bay Rackmount NAS
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Synology RackStation RS1626xs+ 4-Bay Rackmount NAS
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Synology RackStation SA3200D 12-Bay Dual Controller Rackmount NAS
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Synology RackStation RS2825RP+ 16-Bay Rackmount NAS
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Synology ActiveProtect Applicance DP7200
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Synology RackStation SA3400D 12-Bay Dual Controller Rackmount NAS
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Synology RackStation RS4021xs+ 16-Bay Rackmount NAS
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Synology RackStation RS1619xs+ 4-Bay Rackmount NAS
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Synology RackStation RS1221+ & RS1221RP+ 8-Bay Rackmount NAS
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Kurt Paris
With an MSc in Software Engineering, and over 15 years in IT Management, Kurt Paris leads technology strategy at Sirap. Zebra Technologies, Domino and Cisco-certified, he helps Maltese businesses build resilient storage & backup infrastructure, Machine Vision & AutoID Automation
