Performance Compatibility Downloads Compare

DiskStation® DS1821+

High capacity storage and data protection for anyone

DS1821plus
DS1821plus

Designed for scalability and performance

The 8-bay Synology DS1821+ is aimed at IT enthusiast and SMB customers looking for a powerful and scalable storage solution, its business-grade backup solutions keep users safe and protected from potential data loss, while major improvements to compute capabilities and throughput means workloads are finished faster than ever before.

Download Datasheet

CPU

CPU

AMD Ryzen™
Quad-core 2.2 GHz

Cache Acceleration

Cache Acceleration

Dual M.2 2280 slots for NVMe Cache

Performance

Performance

113K 4K random read IOPS1

Scalability

Scalability

Expand up to 18 drives
with two DX517 expansion units

The performance you need

Reduce transfer times with the DS1821+, designed to accelerate your workloads. Easily add faster networking and NVMe drives to further boost performance.

Up to 2,322/1,460 MB/s read/write2

Up to 25GbE networking3

2 x M.2 NVMe cache & storage pool4

The performance you need

Storage that fits your needs

Make the most of high-performance networking and file access without taking up unnecessary space. DS1821+ comes equipped with 8 bays and can scale up to 18 bays with 2 DX517 expansion units as your data needs grow.5

8 bays18 bays

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144 TB324 TB

Storage that fits your needs

Fully certified storage virtualization solutions

Synology iSCSI storage fully supports most virtualization solutions to enhance work efficiency with easy management interface. VMware vSphere 6 and VAAI integration helps offload storage operations and optimizes computation efficiency. Windows Offloaded Data Transfer (ODX) speeds up data transfer and migration rate. OpenStack Cinder support turns your Synology NAS into a block-based storage component.

vmware windows2022 citrix openstack

Ultimate Backup Solution

DS1821+ integrates various backup applications into an intuitive user interface, offering durable storage technologies to safeguard your valuable data on any device.

Active Backup for Business

Active Backup for Business

Centralize backup tasks for VMware, Windows, and file servers. Restore whatever you want fast and reliably when needed.
Learn more

Hyper Backup

Hyper Backup

Comprehensively back up your data to a local shared folder, an external device, another Synology NAS, an rsync server, or a public cloud to ensure data safety.
Learn more

Synology Drive

Synology Drive

Safeguard your computer with Synology Drive Client. Effortlessly perform real-time data backups and point-in-time file recovery.
Learn more

Active Backup for<br>Microsoft 365 / Google Workspace Active Backup for<br>Microsoft 365 / Google Workspace

Active Backup for
Microsoft 365 / Google Workspace

On-premise backup solution with a centralized dashboard. Optimize storage efficiency with single instancing and block-level deduplication technology.
Microsoft 365Google Workspace

Extra protection with Extended Warranty Plus

Extend the standard 3-year hardware warranty of your DS1821+ with 2 more years of Synology-certified support and premium services that help you recover faster in the event of disaster.

Powered by Synology DiskStation Manager

Central Management System

Central Management System

Conveniently manage your fleet of Synology NAS from a centralized console.

Learn more

Synology MailPlus

Synology MailPlus

Secure, reliable, and private mail server solution with an intuitive and modern mail client.

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Synology High Availability

Synology High Availability

Seamless transition between clustered servers in the event of a server failure to minimize the impact on applications.

Learn more

Security

Security

Secure data with comprehensive built-in security tools to protect your devices against evolving threats.

Learn more

Synology Drive

Synology Drive

Instantly access your NAS files across multiple devices whenever you want, wherever you are.

Learn more

Surveillance Station

Surveillance Station

Complete surveillance solution for recording, monitoring, and management.

Learn more

Works best with Synology drives

Engineered to handle intensive 24/7 workloads, Synology drives consistently deliver top-grade performance.

Enterprise Series 3.5" SATA Plus Series 3.5" SATA
Enterprise Series 2.5" SATA Enterprise Series M.2 NVMe
img enterprise-hat img plus-hat3310 img enterprise-sat img enterprise-snv3000

DiskStation® DS1821+

product DS1821plus front view photo
product DS1821plus back view photo
  • 1 Status indicator
  • 2 Alert indicator
  • 3 Power button and indicator
  • 4 LAN indicator
  • 5 Drive status indicator
  • 6 Drive tray
  • 7 Drive tray lock
  • 8 USB 3.2 Gen 1 port
  • 9 Power port
  • 10 System fan
  • 11 PCIe expansion slot
  • 12 Kensington Security Slot
  • 13 Expansion port
  • 14 1GbE RJ-45 port
  • 15 Reset button
  • 16 USB 3.2 Gen 1 port
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Notes:

  1. Performance figures are achieved in the Synology lab with optimized network and configuration settings. Actual performance could vary in different environments. Comparison done against prior-generation 8-bay DS1819+. For full details on the test setup, please visit the Synology performance page here.

  2. Performance figures are obtained through SMB sequential throughput tests using Windows Server 2016 Datacenter on a DS1821+ with a Synology 10GbE NIC and SSD. Actual performance may vary depending on the testing environment, usage, and configuration. See performance charts for more information.

  3. PCIe add-in cards, expansion units, and storage drives are sold separately. Refer to the compatibility list for compatible devices.

  4. Synology SNV3400 series M.2 NVMe SSD drives can be installed through the built-in M.2 slots to enable SSD caching or create SSD storage pools. Drives are sold separately.

  5. Storage figure calculated based on a RAID 5 configuration. Total storage capacity may vary depending on hard drives used and RAID configuration.

Hardware Specifications
CPU
CPU
 CPU Model AMD Ryzen V1500B
CPU Quantity 1
CPU Architecture 64-bit
CPU Frequency 4-core 2.2 GHz
Hardware Encryption Engine
Memory
Memory
 System Memory 4 GB DDR4 ECC SODIMM
Memory Module Pre-installed 4 GB (4 GB x 1)
Total Memory Slots 2
Maximum Memory Capacity 32 GB (16 GB x 2)
Notes
  • Synology reserves the right to replace memory modules with the same or higher frequency based on supplier's product life cycle status. Rest assured that the compatibility and stability have been strictly verified with the same benchmark to ensure identical performance.
  • Please select Synology memory modules for optimum compatibility and reliability. Synology will not provide complete product warranty or technical support if non-Synology memory modules are used for memory expansion.
  • For more information about the recommended memory configurations, please check the Hardware Installation Guide of your Synology product.
Storage
Storage
 Drive Bays 8
Maximum Drive Bays with Expansion Unit 18 (DX517 x 2)
M.2 Drive Slots 2 (NVMe)
Compatible Drive Type* (See all supported drives)
  • 3.5" SATA HDD
  • 2.5" SATA HDD
  • 2.5" SATA SSD
  • M.2 2280 NVMe SSD
Hot Swappable Drive*
Notes
  • The hot swappable drive feature is not supported by M.2 SSD slots.
  • "Compatible drive type" indicates drives that have been tested to be compatible with Synology products. This term does not indicate the maximum connection speed of each drive bay.
External Ports
External Ports
 RJ-45 1GbE LAN Port 4 (with Link Aggregation / Failover support)
USB 3.2 Gen 1 Port* 4
eSATA Port 2
Notes The USB 3.0 standard was renamed to USB 3.2 Gen 1 by the USB Implementers Forum (USB-IF) in 2019.
PCIe
PCIe
 PCIe Expansion 1 x Gen3 x8 slot (x4 link)
Appearance
Appearance
 Size (Height x Width x Depth) 166 mm x 343 mm x 243 mm
Weight 6 kg
Others
Others
 System Fan 120 mm x 120 mm x 2 pcs
Fan Speed Mode
  • Full-Speed Mode
  • Cool Mode
  • Quiet Mode
Easy Replacement System Fan
Brightness Adjustable Front LED Indicators
Power Recovery
Noise Level* 22.2 dB(A)
Scheduled Power On / Off
Wake on LAN / WAN
Power Supply Unit / Adapter 250 W
AC Input Power Voltage 100V to 240V AC
Power Frequency 50/60 Hz, Single Phase
Power Consumption 59.8 W (Access)
26.18 W (HDD Hibernation)
British Thermal Unit 204.05 BTU/hr (Access)
89.33 BTU/hr (HDD Hibernation)
Notes
  • Power consumption is measured when it is fully loaded with Western Digital 1TB WD10EFRX hard drive(s).
  • Noise Level Testing Environment: Fully loaded with Seagate 2TB ST2000VN000 hard drive(s) in the idle state. Two G.R.A.S. Type 40AE microphones, each set up 1 meter away from the Synology NAS at the front and rear. Background noise: 16.49-17.51 dB(A); Temperature: 24.25-25.75˚C; Humidity: 58.2-61.8%
Temperature
Temperature
 Operating Temperature 0°C to 40°C (32°F to 104°F)
Storage Temperature -20°C to 60°C (-5°F to 140°F)
Relative Humidity 5% to 95% RH
Certification
Certification
  • FCC
  • CE
  • BSMI
  • EAC
  • CCC
  • KC
  • VCCI
  • RCM
Warranty
Warranty
 3-year hardware warranty, extendable to 5 years with Extended Warranty Plus
Notes
  • The warranty period starts from the purchase date as stated on your purchase receipt. (Learn more)
  • Extended Warranty Plus is only available in Europe and North America. Refer to the Extended Warranty Plus website for details on supported countries/regions. (Learn more)
Environment
Environment
 RoHS Compliant
Packaging Content
Packaging Content
  • Main Unit X 1
  • Accessory Pack X 1
  • AC Power Cord X 1
  • RJ-45 LAN Cable X 2
  • Quick Installation Guide X 1
Optional Accessories
Optional Accessories
Notes All memory modules will operate at the maximum frequency specified by the CPU manufacturer.

Notes:

  1. Model specifications are subject to change without prior notice.
  2. The figures are based on Synology internal testing. Each performance test is done individually. No other services or applications are processed at the same time.
  3. The actual performance may be lower than lab testing figure due to differences in server configuration, deployment, and the number of active operations.
  4. If usage requirements exceed the specifications above, please contact our regional partners for professional advice.