Synology RackStation Storage Expansion Enclosure or Synology 8-Bay Short-Depth Rackmount NAS? Which Synology Model to Buy
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The synology rackstation storage expansion enclosure vs 8 bay short depth comparison highlights two distinct hardware options for your data infrastructure. Both units are diskless and share the Synology brand, ensuring compatibility with DSM software. The primary difference lies in their function. The RX1217 is an expansion chassis designed to add storage to an existing system. The RS1221+ is a standalone NAS with its own processing power and RAM. You must choose between scaling capacity or deploying a new server.
Key differences
| Aspect | Synology RackStation Storage Expansion Enclosure | Synology 8-Bay Short-Depth Rackmount NAS |
|---|---|---|
| Function | Storage expansion enclosure | Standalone NAS server |
| RAM Capacity | not listed | 4GB DDR4 |
| Dimensions (H x W x D) | 3.46 x 17 x 25.4 inches | 8.5 x 16.5 x 23 inches |
| Height (U) | 2U (approx) | 2U (approx) |
| Network Performance | Depends on host NAS | Up to 5x improvement with PCIe card |
Which one should you choose?
Choose Synology RackStation Storage Expansion Enclosure if
- You need to add more drive bays to an existing RackStation system without replacing your main server.
- You want a plug-and-use solution for online volume expansion managed from DSM.
- Your current NAS has available expansion ports and you only require additional storage space.
Choose Synology 8-Bay Short-Depth Rackmount NAS if
- You need a complete, standalone NAS unit with its own processor and 4GB of RAM.
- You want to configure two units together for a Synology High Availability cluster for maximum uptime.
- You require high read speeds of up to 2,315 MB/s for multi-user environments.
Verdict: The RX1217 is the correct choice if you already own a compatible RackStation and simply need more storage capacity. The RS1221+ is the better option if you are building a new infrastructure or require a standalone server with its own processing resources and high availability features.
Specs: Expansion vs NAS
Core function
The Synology RackStation Storage Expansion Enclosure (RX1217) serves strictly as an expansion unit. It plugs into an existing Synology NAS to add storage capacity online without downtime. The Synology 8-Bay Short-Depth Rackmount NAS (RS1221+) is a standalone server. It processes data, manages files, and runs applications independently. You need a primary NAS to use the RX1217. The RS1221+ works on its own or in a cluster. Choose the expansion unit only if you already own a compatible Synology system.
Storage bays
Both products are diskless and include no hard drives. The RX1217 adds eight drive slots to your existing infrastructure. The RS1221+ also provides eight drive slots for its own volume. Neither unit contains internal memory or storage media out of the box. You must purchase drives separately for either model. The capacity you get depends entirely on the drives you install. Both offer the same slot count, so storage expansion potential is equal per unit.
Form factor
The RX1217 measures 17 inches wide, 3.46 inches high, and 25.4 inches long. It weighs 28 pounds. This is a standard 2U rackmount depth. The RS1221+ measures 16.5 inches wide, 8.5 inches high, and 23 inches long. It is described as having a short depth of 298 mm. The RS1221+ is taller but slightly shorter in depth. The RX1217 is wider and deeper. Check your rack space carefully. The RS1221+ may fit better in tight front-access scenarios due to its reduced depth.
RAM capacity
The data lists 4GB of DDR4 RAM for the RS1221+. This memory supports its processing tasks and multi-user environments. The RX1217 is an expansion enclosure. It does not have its own processor or active RAM for data handling. It relies on the host NAS for all computational power. The RS1221+ has a clear advantage here because it is an active server node. The expansion unit has no independent memory capacity to compare.
Performance specs
The RS1221+ lists specific throughput speeds: up to 2,315 MB/s read and 1,147 MB/s write. It also mentions improving network performance by five times with compatible PCIe cards. The RX1217 has no listed performance numbers. It transfers data at the speed of the connected host NAS. The RS1221+ provides its own hardware acceleration and network options. The expansion unit is passive. You get defined performance metrics only with the standalone NAS.
High availability
The RS1221+ supports Synology High Availability (SHA) clustering. You can pair two units for minute-level failover and maximum uptime. The RX1217 cannot form a cluster. It is a passive storage shelf. It cannot provide failover services on its own. If you need redundancy at the server level, the RS1221+ is the only option. The expansion unit only adds capacity to a single active node.
Choose the right Synology hardware
You need more space for existing NAS
The RX1217 is a diskless expansion enclosure designed to plug into your current Synology RackStation system. It allows you to add storage capacity online without downtime. This unit measures 25.4 inches in length and weighs 28 pounds. It is managed directly from DSM, making it a seamless upgrade for your existing infrastructure rather than a new server.
You require a standalone high-performance server
The RS1221+ is a standalone 8-bay NAS with 4GB of RAM. It offers up to 2,315 MB/s read speeds and 1,147 MB/s write speeds. You can improve network performance five times with compatible SFP+ or RJ-45 cards. It also supports Synology High Availability clusters for minute-level failover, providing maximum service uptime for multi-user environments.
You need a short-depth rackmount unit
If rack depth is a constraint, the RS1221+ features a short depth of just 298 mm. It stands 8.5 inches high and is 16.5 inches wide. This compact form factor fits well in tight server racks while still providing eight drive bays and robust performance capabilities for your data storage needs.
The products compared
Synology RackStation Storage Expansion Enclosure
Best for: expanding existing RackStation storage capacity
- Included Storage
- Diskless
- Dimensions
- 25.4 × 17 × 3.46 inches
- Weight
- 28 pounds
View on Amazon: Synology RackStation Storage Expansion Enclosure Affiliate link
The Synology RX1217 is an 8-bay diskless expansion unit for RackStation systems. It measures 25.4 by 17 by 3.46 inches and weighs 28 pounds. You can expand storage online while the system runs. Management happens through Synology DiskStation Manager. It fits users who need more drive slots without buying a new server.
Pros
- 8 drive bays for high capacity
- Diskless design reduces upfront cost
- Supports online volume expansion
- Managed via Synology DSM
Cons
- No internal drives included
- Requires compatible RackStation host system
- Heavier build at 28 pounds
Good fit if
- You need to add 8 drive slots
- You already own a compatible RackStation
- You want to expand storage online
Skip if
- You need a standalone NAS
- You want pre-loaded drives
- You lack a compatible host system
Verdict: Synology RX1217 8-Bay Rack Expansion is for users who already have a compatible RackStation and need more drive bays without buying a new server.
Synology 8-Bay Short-Depth Rackmount NAS
Best for: Compact 8-bay rack storage with HA support
- Drive Bays
- 8 Bay
- Included Storage
- Diskless
- RAM Capacity
- 4GB RAM
- Dimensions
- 23 × 16.5 × 8.5 inches
View on Amazon: Synology 8-Bay Short-Depth Rackmount NAS Affiliate link
The Synology RS1221+ is a diskless 8-bay rackmount NAS with a short depth of 298 mm. It includes 4GB of RAM and delivers up to 2,315 MB/s read speeds. You can upgrade network performance by adding a PCIe SFP+ or RJ-45 card. The unit supports Synology High Availability clusters for service uptime. It suits users needing high capacity in a compact rack footprint.
Pros
- Short depth of 298 mm for tight rack spaces
- Up to 2,315 MB/s read performance
- Supports Synology High Availability clustering
- Expandable network via PCIe cards
Cons
- Sold diskless with no included storage
- Only 4GB base RAM capacity
- Requires separate purchase of drives and cards
Good fit if
- You need 8 bays in a short-depth rack
- You want to build a high-availability cluster
- You plan to add specific network cards
Skip if
- You require included hard drives
- You need more than 4GB base RAM
- You prefer a standard depth chassis
Verdict: Synology RS1221+ 8-Bay RackStation is a compact 8-bay solution for users needing high read speeds and HA clustering in a short-depth rack. It fits those who will add their own drives and network upgrades.
Specifications side by side
| Spec | Synology RackStation Storage Expansion Enclosure | Synology 8-Bay Short-Depth Rackmount NAS |
|---|---|---|
| Drive Bays | not stated | 8 Bay |
| Included Storage | Diskless | Diskless |
| Number of Bays | not stated | 8-Bay |
| RAM Capacity | not stated | 4GB RAM |
| Dimensions | 25.4 × 17 × 3.46 inches | 23 × 16.5 × 8.5 inches |
| Weight | 28 pounds | not stated |
| Size | 88 mm x 482 mm x 696 mm | RS1221+ |
| Color | Black | Black |
| Model | RX1217 | RS1221+ |
Frequently asked questions
Can I use the Synology RX1217 as a standalone server?
No. The RX1217 is a storage expansion enclosure. It requires an existing compatible Synology RackStation to function. It does not operate independently. You must connect it to a host NAS to add drive bays and increase storage capacity for your current system.
Does the RS1221+ come with hard drives installed?
No. This model is diskless. You must purchase and install your own hard drives. The unit provides the eight drive bays and the server infrastructure, but the storage media is not included. You are responsible for selecting and inserting the drives yourself.
Which unit supports high availability clustering?
The RS1221+ supports HA clustering. This feature allows for high availability and high read speeds. The RX1217 is an expansion unit and does not offer standalone HA capabilities. Choose the RS1221+ if you need redundant server operations without an existing host.
What are the physical dimensions of the RS1221+?
The RS1221+ measures 16.5 inches wide, 8.5 inches high, and 23 inches long. It is a short-depth rackmount solution. These dimensions allow it to fit into standard racks while providing eight drive bays for compact storage deployment in your data center.
How much RAM does the RS1221+ have?
The RS1221+ includes 4GB of RAM. This memory supports the NAS operations and file services. The RX1217 has no listed RAM capacity as it relies on the host system. Check your specific model requirements to ensure the RAM meets your workload needs.
Can I add the RX1217 to a non-Synology NAS?
No. The RX1217 is designed exclusively for Synology RackStation systems. It ensures compatibility with DSM software and Synology hardware. You cannot connect it to third-party NAS brands. It must be paired with a compatible Synology host to expand storage online.
What is the weight of the RX1217 expansion unit?
The RX1217 weighs 28 pounds. This weight includes the chassis and internal components. It is a black unit measuring 88 mm in height. Ensure your rack can support this weight when planning the installation of the expansion enclosure alongside your existing server.