Synology Network Attached Storage DS1821+ 8bay NAS DiskStation AMD Ryzen V1500B 4GB DDR4 Retail

MPN
DS1821+
CPU
CPU Model
AMD Ryzen V1500B
CPU Architecture
64-bit
CPU Frequency
4-core 2.2 GHz
Hardware Encryption Engine (AES-NI)
Yes

Storage
Drive Bays
8
Maximum Drive Bays with Expansion Unit
18 (DX517 x 2)
M.2 Drive Slots
2 (NVMe)
Compatible Drive Type
3.5" SATA HDD
2.5" SATA HDD
2.5" SATA SSD
M.2 2280 NVMe SSD
Maximum Single Volume Size
108 TB
Hot Swappable Drive
Yes
Notes
"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.
Each internal volume (may consist of multiple drives) is expandable up to 108TB.

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 Expansion
1 x Gen3 x8 slot (x4 link)

File System
Internal Drives
Btrfs
EXT4
External Drives
Btrfs
EXT4
EXT3
FAT
NTFS
HFS+
exFAT
Notes
exFAT Access is purchased separately in Package Center.

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
Yes
Brightness Adjustable Front LED Indicators
Yes
Power Recovery
Yes
Noise Level
22.2 dB(A)
Scheduled Power On / Off
Yes
Wake on LAN / WAN
Yes
Power Supply Unit / Adapter
250 W
AC Input Power Voltage
100 V to 240 V 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^oC, Humidity: 58.2-61.8%

Temperature
Operating Temperature
0^oC to 40^oC (32^oF to 104^oF)
Storage Temperature
-20^oC to 60^oC (-5^oF to 140^oF)
Relative Humidity
5% to 95% RH

Certification
FCC
CE
BSMI
EAC
CCC
KC
VCCI
RCM

Environment
RoHS Compliant

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
DDR4 ECC SODIMM: D4ES01-4G/D4ES01-8G/D4ECSO-2666-16G
Expansion Units: DX517
3.5" SATA HDD: HAT5300
2.5" SATA SSD: SAT5200
M.2 2280 NVMe SSD: SNV3400
25GbE Network Interface Card: E25G21-F2
10GbE Network Interface Card: E10G21-F2/E10G18-T2/E10G18-T1
VisualStation: VS960HD/VS360HD
Surveillance Device License Pack
Notes
All memory modules will operate at the maximum frequency specified by the CPU manufacturer.

DSM Specifications

Storage Management
Maximum Internal Volume Number
64
SSD Read / Write Cache
Yes
SSD TRIM
Yes
Supported RAID Type
Synology Hybrid RAID
Basic
JBOD
RAID 0
RAID 1
RAID 5
RAID 6
RAID 10
RAID Migration
Basic to RAID 1
Basic to RAID 5
RAID 1 to RAID 5
RAID 5 to RAID 6
Volume Expansion with Larger HDDs
Synology Hybrid RAID
RAID 1
RAID 5
RAID 6
RAID 10
Volume Expansion by Adding a HDD
Synology Hybrid RAID
JBOD
RAID 5
RAID 6
Global Hot Spare Supported RAID Type
Synology Hybrid RAID
RAID 1
RAID 5
RAID 6
RAID 10

File Services
File Protocol
CIFS/AFP/NFS/FTP/WebDAV
Maximum Concurrent CIFS/AFP/FTP Connections
1,000
Maximum Concurrent CIFS/AFP/FTP Connections (with RAM expansion)
2,000
Windows Access Control List (ACL) Integration
Yes
NFS Kerberos Authentication
Yes
Notes
Regarding data concerning tests with RAM expansion, all memory slots are installed with the maximum capacity of supported RAM.
The testing standard was based on the maximum number of concurrent connections supported by this model. During the testing, 25% of the connections were used to transfer files concurrently. The transfer process guaranteed that the connections were not interrupted, the minimum transfer speed was not guaranteed.

Account and Shared Folder
Maximum Local User Accounts
2,048
Maximum Local Groups
256
Maximum Shared Folder
512
Maximum Shared Folder Sync Tasks
16

High Availability
Synology High Availability
Yes

Log Center
Syslog Events per Second
800

Virtualization
VMware vSphere with VAAI
Yes
Windows Server 2016
Yes
Windows Server 2019
Yes
Citrix Ready
Yes
OpenStack
Yes

General Specifications
Networking Protocols
SMB1 (CIFS), SMB2, SMB3, NFSv3, NFSv4, NFSv4.1, NFS Kerberized sessions, iSCSI, HTTP, HTTPs, FTP, SNMP, LDAP, CalDAV
Supported Browsers
Google Chrome
Firefox
Microsoft Edge
Internet Explorer 10 onwards
Safari 10 onwards
Safari (iOS 10 onwards)
Google Chrome (Android 6.0 onwards)
Supported Language
English, Deutsch, Franais, Italiano, Espaol, Dansk, Norsk, Svenska, Nederlands, , Polski, Magyar, Portugus do Brasil, Portugus Europeu, Trke, esk, , , , ,

Add-on Packages

Antivirus by McAfee (Trial)
Yes

Central Management System
Yes

Synology Chat
Maximum Users
1,500
Notes
The number of concurrent HTTP connections for Synology Chat was configured to the maximum.
For tested models with expandable memory, the maximum amount of RAM was installed.

Document Viewer
Yes

Download Station
Maximum Concurrent Download Tasks
80

exFAT Access (Optional)
Yes

iSCSI Manager
Maximum iSCSI Target Number
128
Maximum iSCSI LUN
256
iSCSI LUN Clone/Snapshot, Windows ODX
Yes

Synology MailPlus / MailPlus Server
Free Email Accounts
5
Maximum Number of Concurrent Users
150
Maximum Server Performance
1,484,000 emails per day, approx. 45GB
Notes
Models with more than 4 bays were installed with two SSDs for SSD cache.
For tested models with expandable memory, the maximum amount of RAM was installed.
The performance of the mail system will slightly decrease in high-availability mode due to data synchronization between the two servers.
Functions that were enabled in all of the tests above: anti-spam, anti-virus, DNSBL, greylist, content scan, full-text search (English only).

Media Server
DLNA Compliance
Yes

Moments
Facial Recognition
Yes
Subject Recognition
Yes
Auto Color and Rotate
Yes
Moments Select
Yes

Snapshot Replication
Maximum Snapshots per Shared Folder
1,024
Maximum of System Snapshots
65,536

Surveillance Station
Maximum IP cam
40 (including 2 Free License)
Total FPS (H.264)
1200 FPS at 720p (1280x720)
1050 FPS at 1080p (1920x1080)
600 FPS at 3M (2048x1536)
440 FPS at 5M (2591x1944)
320 FPS at 4K (3840x2160)
Total FPS (H.265)
1200 FPS at 720p (1280x720)
1200 FPS at 1080p (1920x1080)
1120 FPS at 3M (2048x1536)
600 FPS at 5M (2591x1944)
480 FPS at 4K (3840x2160)
Notes
Surveillance Station throughput is tested with Axis network camera, using continuous recording with live view from Surveillance Station and motion detection by camera. Live view and recording are sharing the same stream from the camera.
The maximum channel number also includes devices installed on Virtual DSM.
Total FPS may be affected by other services running at the same time (e.g., archive tasks performed by Archive Vault).

Synology Drive
Recommended Number of Hosted Files
1,000,000 (applies to files indexed or hosted by Synology Drive. For file access through other standard protocols, refer to the File Services section above)
Recommended Number of Concurrent Sync Clients
550 (the number of connections that can be maintained when the recommended number of hosted files was reached)
Notes
Exceeding the recommended numbers above will not block application operations, but may result in longer response time.
Utilizing SSD cache can significantly improve performance.
For tested models with expandable memory, the maximum amount of RAM was installed.
Btrfs file system and non-encrypted shared folders were used during the aforementioned testing.

Synology Office
Maximum Users
1,800
Notes
Multiple files were opened for testing and each file was edited by 30 users simultaneously.
For tested models with expandable memory, the maximum amount of RAM was installed.
Client performance may affect maximum simultaneous editing users. Client PCs used for testing: Intel Core i3-3220 / 8GB RAM

Video Station
Yes

Virtual Machine Manager
Recommended Virtual Machine Instances
8
Recommended Virtual DSM Number
8 (including 1 Free License)
Notes
The specifications vary depending on system configuration and memory size.

VPN Server
Maximum Connections
30