I recently purchased a Synology NAS. The model names initially appeared to be hugely unfriendly slugs like “DS1814+” and “RS3617xs”.

After some time, I realized that they’re much more easily understood once you know how those model names are built:

[Family][Max Drives][Refresh Cycle][Tier]

The Breakdown

Family

The Family is the broadest grouping, and generally a form factor:

• DSxxx for the desktop DiskStation line
• RSxxx for the rack-mounted RackStation line
• etc.

Max Drives

The Max Drives is the key distinguishing factor within a family:

• A DS2xx has two bays.
• A DS4xx has four bays.
• A DS18xx has eight bays, but you can connect up to two 5-bay expansion units, for a total of eighteen.

Refresh Cycle

Like most (all?) manufacturers, Synology periodically updates all of their products with better CPUs, more RAM, or some other improvement that doesn’t change the Family or Max Drive characteristics. These generally happen at the same time across all products.

DS418x are from the “18” cycle. They replaced the DS416x, which replaced the DS414x, and so on.

Tier

Synology also makes several “series” of drives that share characteristics. Think of them as tiers like basic, mid-level, premium.

DS218+ and DS218 are both desktop 2 bay NAS from the 18 lineup, but the former is from the “Plus” series and the latter is from the “Value” series.

Sidenote

The expansion units can lead to some non-obvious results. For four bay desktop units, you may be looking at the DS418, DS418play, and DS918+. Upgrading to the “play” version gets you beefier specs for transcoding and streaming media. Upgrading to the “plus” version lets you use a 5 bay expansion unit. Which is why it is not called the DS418+ but the DS918+.