Synology DS1821+ Review

The Synology DS1821+ is a 8-bay network attached storage that has something very different under its hood. That is, it uses the AMD Ryzen CPU and this is Synology’s second NAS with AMD CPU after the DS1621+ 6-bay NAS. Other than this change from the Intel incumbent, the DS1821+ sports two M.2 2280 slots for NVMe cache and expands up to 18 drives with two D517 expansion units. IT enthusiasts and SMBs would be delighted to learn that Synology highlighted major improvements to its compute capabilities over its predecessor (DS1819+).

From Intel Atom C3538 to AMD Ryzen V1500B

Synology has mainly been using Intel processors right up until the DS1819+ on Intel Atom C3538 before switching to AMD for the 21+ lineup. Both Synology DS1621+ and DS1821+ are using AMD Ryzen V1500B CPU.

Technical Specifications of AMD Ryzen V1500B and Intel Atom C3538

AMD Ryzen V1500B Intel Atom C3538
Market segment Embedded Server
Manufacturer AMD Intel
CPU part number YE1500C4T4MFB HW8076502444301
Introduction date 2018 15 Aug 2017
Frequency (MHz) 2,200 2,100
L1 cache 256 KB (code)
128 KB (data)
128 KB (code)
96KB (data)
L2 cache (MB) 2 8
L3 cache (MB) 4
TDP (W) 16 15
Cores 4
Threads 8 4
Hyper-threading Yes No

System Performance

Looking at the technical specifications of both AMD Ryzen V1500B and Intel Atom C3538, the higher clock speed, threads and larger L1 cache suggests better overall system performance.

Hardware Video Transcoding

There are no hardware video transcoding capabilities as both Intel Atom C3538 and AMD Ryzen V1500B does not come with processor graphics. That is, it would not be as fast as those with hardware video transcoding capabilities. However, it will not be awfully slow due to the more capable CPU. If you have been happy with video transcoding speeds on the Synology DS1817+ then you would be fine with the DS1821+ because the DS1817+ does not come with hardware transcoding capability too.

Some of the past Synology NAS that have hardware videos transcoding capability are those with Intel Celeron J3455 CPU (DS1019+, DS918+, etc.) and Intel Celeron J3355 (DS418play, DS218+).

Verdict of changing to AMD Ryzen V1500B

In my opinion, you will get improved system performance due to the change from Intel Atom to AMD Ryzen V1500B in the 21+ lineup. While you will not enjoy hardware transcoding capabilities, transcoding jobs will still be faster on the AMD Ryzen V1500B than the Intel Atom C3538 owing to its better technical specifications.

Synology DS1821+’s Technical Specifications

Synology DS1821+ Network Attached Storage
Processor AMD Ryzen V1500B
Quad-core 2.2 GHz
Memory 2 x Memory Slots
(Expandable to 32GB ECC)
Encryption Yes (AES-NI)
Storage 8 x 3.5"/2.5" SATA II/III; Hot Swappable
Maximum of 18 drives with DX517
2 x M.2 NVMe Drive Slots
Capacity 108 TB maximum single volume size
Networking 4 x 1GbE
Supports Link Aggregation/Failover
Connectors 4 x USB3.2 Gen 1
2 x eSATA
PCIe 1 x Gen3 x8 slot (x8 link)
Supporting 25GbE or 10GbE Network Interface Card
Dimensions (mm) 166 x 343 x 243
Warranty 3-year
(Optional 2-year extended warranty available)
Weight 6.0 kg
Power Consumption 59.8 W (Access)
26.18 W (HDD Hibernation)
Power Supply Unit 250 W
System Fan 2 x 120mm
Noise Level 22.2 dB(A)
SRPS$1,598 (8GB)

Unboxing the Synology DS1821+

The DS1821+ package comes with:

  • Synology DS1821+ NAS
  • Pack of screws for mounting 2.5″ and M.2 drives
  • Keys for securing the drive bays
  • Installation guide
  • Power cord
  • Two (2) Ethernet patch cords

Similar to the previous 8-bays, the power cord plugs directly into the DS8121+ NAS ‘s power supply unit. Hence, there is no ‘power brick’.

Taking a look at the Synology DS1821+

The front of the DS1821+ NAS

The DS1821+ is matte-black except for its base. The front bezel and back are made of plastic while the rest of the body is made of metal.

Located above the drive bays are the power button and status indicators.

Removing the drive trays reveals the SATA backplane where the hard drives are attached to. In full view are the two (2) 120mm system fans that draw heat away from the hard drives into the surrounding environment.

On the left side are two M.2 NVMe drive slots to super-charge the NAS performance.

A light press near the bottom edge of the drive tray releases the handle and unlatches the drive tray from the NAS. The drive tray can be locked in place with the provided key.

The back of the DS1821+ NAS

At the center of the DS1821+ NAS are two (2) 120mm system fans. To the left are the IEC-320-C14 power connector and Kensington lock slot. To the right of it is the PCIe slot for additional Synology accessories like 25GbE or 10GbE Network Interface Card.

Near the bottom are the eSATA port, four (4) Gigabit LAN ports, reset button, three (3) USB 3.2 Gen 1 ports and eSATA port.

Setting up the Synology DS1821+

Installing the RAM

The D4ES01-8G 8GB DDR4 ECC Unbuffered SODIMM is from Synology and compatible with Synology 21-Series NAS arrays, including the DS1821+, DS1621xs+ and DS1621+.

The RAM slots are located at the “belly” of the DS1821+ NAS. The RAM upgrading process is straight-forward which involves a Phillips-head screw driver. Installing the new RAM modules took less than five (5) minutes.

Installing the hard drives

I am using the Seagate Barracuda Pro 10TB (ST10000DM0004) hard drives in the Synology DS1821+ NAS. Do note that the Seagate Barracuda Pro hard drives are neither listed in Synology Product Compatibility List nor incompatible list.

These are CMR (Conventional Magnetic Recording) hard drives and are better for NAS usage compared to SMR (Shingled Magnetic Recording). Seagate has a page listing which of their products are using CMR and SMR.

Just some key advantages of Seagate Barracuda Pro series. They are 7,200 RPM drives with sustained data rates up to 250 MB/s and burst data rate of 6 Gb/s. They also have 300TB/year workload limit and MTBF of 1M hours which makes them great for home servers.


With regard to the CPU change from Intel to AMD, I observed that the DSM on DS1821+ is more responsive compared to DS1817+. It could be my imagination but operations within packages like Docker, Video Station, etc. are definitely faster. Media indexing and thumbnails generation for Synology Moments are noticeably faster on DS1821+ compared to DS1817+.

For those who primarily use their Synology NAS as media server (Plex, DS Video Station, etc.), the lack of hardware transcoding capability would be a concern. What Synology could potentially do in the future is continuing having a couple of offerings that uses CPU with graphics capability like the DS1019+ and DS918+ in recent years.

Other than hardware transcoding, the improved performance from the CPU change is great for users who only have a handful of media transcoding tasks in their workloads.

Lastly, the out-of-the-box support for two M.2 NVMe cache drives is a nice touch. This frees up the PCIe slot for 25GbE or 10GbE network card.

All in all, I am glad that I upgraded to the Synology DS1821+ NAS.

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