1. products list

Comparison results

DS1621+ DS1821+
DS1621+ DS1821+
Hardware Specs
Hardware Specifications
CPU
CPU Model AMD Ryzen_V1500B AMD Ryzen_V1500B
CPU Quantity 1 1
CPU Core 4 4
CPU Architecture 64-bit 64-bit
CPU Frequency 2.2 GHz 2.2 GHz
Hardware Encryption Engine
Memory
System Memory 4 GB DDR4 ECC SODIMM 4 GB DDR4 ECC SODIMM
Memory Module Pre-installed 4 GB (4 GB x 1) 4 GB (4 GB x 1)
Total Memory Slots 2 2
Maximum Memory Capacity 32 GB (16 GB x 2) 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.
  • 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
Drive Bays 6 8
Maximum Drive Bays with Expansion Unit 16 (DX517 x 2) 18 (DX517 x 2)
M.2 Drive Slots 2 (NVMe) 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
  • 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.
  • 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
RJ-45 1GbE LAN Port 4 (with Link Aggregation / Failover support) 4 (with Link Aggregation / Failover support)
USB 3.2 Gen 1 Port* 3 4
eSATA Port 2 2
Notes The USB 3.0 standard was renamed to USB 3.2 Gen 1 by the USB Implementers Forum (USB-IF) in 2019. 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) 1 x Gen3 x8 slot (x4 link)
Appearance
Size (Height x Width x Depth) 166 mm x 282 mm x 243 mm 166 mm x 343 mm x 243 mm
Weight 5.1 kg 6 kg
Others
System Fan 92 mm x 92 mm x 2 pcs 120 mm x 120 mm x 2 pcs
Fan Speed Mode
  • Full-Speed Mode
  • Cool Mode
  • Quiet Mode
  • Full-Speed Mode
  • Cool Mode
  • Quiet Mode
Easy Replacement System Fan
Brightness Adjustable Front LED Indicators
Power Recovery
Noise Level* 25.2 dB(A) 22.2 dB(A)
Scheduled Power On / Off
Wake on LAN / WAN
Power Supply Unit / Adapter 250 W 250 W
AC Input Power Voltage 100V to 240V AC 100V to 240V AC
Power Frequency 50/60 Hz, Single Phase 50/60 Hz, Single Phase
Power Consumption 51.22 W (Access)
25.27 W (HDD Hibernation)		 59.8 W (Access)
26.18 W (HDD Hibernation)
British Thermal Unit 174.77 BTU/hr (Access)
86.22 BTU/hr (HDD Hibernation)		 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%
  • 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
Operating Temperature 0°C to 40°C (32°F to 104°F) 0°C to 40°C (32°F to 104°F)
Storage Temperature -20°C to 60°C (-5°F to 140°F) -20°C to 60°C (-5°F to 140°F)
Relative Humidity 5% to 95% RH 5% to 95% RH
Certification
  • FCC
  • CE
  • BSMI
  • EAC
  • CCC
  • KC
  • VCCI
  • RCM
  • FCC
  • CE
  • BSMI
  • EAC
  • CCC
  • KC
  • VCCI
  • RCM
Warranty 3-year hardware warranty, extendable to 5 years with EW201 or Extended Warranty Plus 3-year hardware warranty, extendable to 5 years with EW201 or 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. EW201/EW202 is only available in Asia, Africa, and Oceania. For exact availability information please visit their respective websites.
  • 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. EW201/EW202 is only available in Asia, Africa, and Oceania. For exact availability information please visit their respective websites.
Environment RoHS Compliant 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
  • 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
Notes All memory modules will operate at the maximum frequency specified by the CPU manufacturer. All memory modules will operate at the maximum frequency specified by the CPU manufacturer.
Software Specs
DSM Specifications
Storage Management
Maximum Single Volume Size 108 TB 108 TB
Maximum Internal Volume Number 64 64
M.2 SSD Storage Pool Support*
SSD Read/Write Cache (Determining cache size)
SSD TRIM
Supported RAID Type
  • Synology Hybrid RAID
  • Basic
  • JBOD
  • RAID 0
  • RAID 1
  • RAID 5
  • RAID 6
  • RAID 10
  • 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
  • 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
  • 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
  • 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
  • Synology Hybrid RAID
  • RAID 1
  • RAID 5
  • RAID 6
  • RAID 10
Notes
  • Creating M.2 storage pools requires the use of Synology-verified SSDs, which are rigorously tested under extreme temperature conditions. Thermal parameters for SSDs and NAS units are fine-tuned to ensure optimal management of thermal conditions under I/O-intensive environments. (Learn more)
  • Usable capacity for each volume will be lower than the maximum volume size and is dependent on the filesystem and the amount of system metadata stored.
  • Each internal volume (may consist of multiple drives) is expandable up to 108TB.
  • Creating M.2 storage pools requires the use of Synology-verified SSDs, which are rigorously tested under extreme temperature conditions. Thermal parameters for SSDs and NAS units are fine-tuned to ensure optimal management of thermal conditions under I/O-intensive environments. (Learn more)
  • Usable capacity for each volume will be lower than the maximum volume size and is dependent on the filesystem and the amount of system metadata stored.
  • Each internal volume (may consist of multiple drives) is expandable up to 108TB.
File System
Internal Drives
  • Btrfs
  • ext4
  • Btrfs
  • ext4
External Drives
  • Btrfs
  • ext4
  • ext3
  • FAT
  • NTFS
  • HFS+
  • exFAT
  • Btrfs
  • ext4
  • ext3
  • FAT
  • NTFS
  • HFS+
  • exFAT
Notes exFAT Access can be installed for free from Package Center in DSM 7.0. In DSM 6.2 or earlier versions, exFAT Access needs to be purchased in Package Center. exFAT Access can be installed for free from Package Center in DSM 7.0. In DSM 6.2 or earlier versions, exFAT Access needs to be purchased in Package Center.
File Services
File Protocol
  • SMB
  • AFP
  • NFS
  • FTP
  • WebDAV
  • Rsync
  • SMB
  • AFP
  • NFS
  • FTP
  • WebDAV
  • Rsync
Maximum Concurrent SMB/AFP/FTP Connections 1,000 1,000
Maximum Concurrent SMB/AFP/FTP Connections (with RAM expansion) 2,000 2,000
Windows Access Control List (ACL) Integration
NFS Kerberos Authentication
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.
  • 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 & Shared Folder
Maximum Local User Accounts 2,048 2,048
Maximum Local Groups 256 256
Maximum Shared Folder 512 512
Maximum Shared Folder Sync Tasks 16 16
Hybrid Share
Maximum Hybrid Share Folders 10 10
Hyper Backup
Folder and Package Backup
Entire System Backup
Notes Full-system backup requires DSM 7.2 or later. Full-system backup requires DSM 7.2 or later.
High Availability
Synology High Availability
Log Center
Syslog Events per Second 1,000 1,000
Virtualization
VMware ESXi 6.5 and VAAI
Windows Server 2016
Windows Server 2019
Windows Server 2022
Citrix Ready
OpenStack
General Specifications
Supported Protocols SMB1 (CIFS), SMB2, SMB3, NFSv3, NFSv4, NFSv4.1, NFS Kerberized sessions, iSCSI, HTTP, HTTPs, FTP, SNMP, LDAP, CalDAV SMB1 (CIFS), SMB2, SMB3, NFSv3, NFSv4, NFSv4.1, NFS Kerberized sessions, iSCSI, HTTP, HTTPs, FTP, SNMP, LDAP, CalDAV
Supported Browsers
  • Chrome
  • Firefox
  • Edge
  • Safari
  • Chrome
  • Firefox
  • Edge
  • Safari
Supported Language English, Deutsch, Français, Italiano, Español, Dansk, Norsk, Svenska, Nederlands, Русский, Polski, Magyar, Português do Brasil, Português Europeu, Türkçe, Český, ภาษาไทย, 日本語, 한국어, 繁體中文, 简体中文 English, Deutsch, Français, Italiano, Español, Dansk, Norsk, Svenska, Nederlands, Русский, Polski, Magyar, Português do Brasil, Português Europeu, Türkçe, Český, ภาษาไทย, 日本語, 한국어, 繁體中文, 简体中文
Notes For an updated list of supported browser versions, check the DSM Technical Specifications. For an updated list of supported browser versions, check the DSM Technical Specifications.
Add-on Packages view the complete package list
Antivirus by McAfee (Trial)
Central Management System
Synology Chat
Suggested Maximum Users 1,500 1,500
Suggested Concurrent Users 150 150
Notes When applicable, systems are tested configured with maximum memory and set to allow the maximum number of connections. When applicable, systems are tested configured with maximum memory and set to allow the maximum number of connections.
Download Station
Maximum Concurrent Download Tasks 80 80
SAN Manager
Maximum iSCSI Target Number 128 128
Maximum LUN 256 256
LUN Clone/Snapshot, Windows ODX
Notes iSCSI Manager has been renamed to SAN Manager in DSM 7.0. iSCSI Manager has been renamed to SAN Manager in DSM 7.0.
Synology MailPlus / MailPlus Server
Free Email Accounts 5 (Additional accounts require purchase of licenses) 5 (Additional accounts require purchase of licenses)
Suggested Maximum Users 750 750
Suggested Concurrent Users 150 150
Maximum Server Performance 1,484,000 emails per day, approx. 45GB 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).
  • 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
Synology Photos
Facial Recognition
Object Recognition
Snapshot Replication
Maximum Snapshots per Shared Folder 1,024 1,024
Maximum of System Snapshots 65,536 65,536
Surveillance Station
Default Licenses 2 (Additional cameras require purchase of licenses) 2 (Additional cameras require purchase of licenses)
Suggested Maximum IP Cameras and Total FPS (H.264)
  • 720p: 40 channels, 1200 FPS
  • 1080p: 40 channels, 1050 FPS
  • 3M: 40 channels, 600 FPS
  • 5M: 40 channels, 440 FPS
  • 4K: 32 channels, 320 FPS
  • 720p: 40 channels, 1200 FPS
  • 1080p: 40 channels, 1050 FPS
  • 3M: 40 channels, 600 FPS
  • 5M: 40 channels, 440 FPS
  • 4K: 32 channels, 320 FPS
Suggested Maximum IP Cameras and Total FPS (H.265)
  • 720p: 40 channels, 1200 FPS
  • 1080p: 40 channels, 1200 FPS
  • 3M: 40 channels, 1120 FPS
  • 5M: 40 channels, 600 FPS
  • 4K: 40 channels, 480 FPS
  • 720p: 40 channels, 1200 FPS
  • 1080p: 40 channels, 1200 FPS
  • 3M: 40 channels, 1120 FPS
  • 5M: 40 channels, 600 FPS
  • 4K: 40 channels, 480 FPS
Notes
  • Performance figures are obtained from testing conducted with the device fully populated with drives, with their default memory configuration, and under a continuous recording setup. Actual system capabilities may vary based on configuration, drive performance, enabled features, and the presence of additional workloads.
  • Use NVR Selector to quickly find a suitable model based on your requirements.
  • The maximum number of camera stream outputs is 2 times the suggested maximum number of IP cameras.
  • Performance figures are obtained from testing conducted with the device fully populated with drives, with their default memory configuration, and under a continuous recording setup. Actual system capabilities may vary based on configuration, drive performance, enabled features, and the presence of additional workloads.
  • Use NVR Selector to quickly find a suitable model based on your requirements.
  • The maximum number of camera stream outputs is 2 times the suggested maximum number of IP cameras.
Synology Drive
Recommended Number of Concurrent Sync Clients 550 (the number of connections that can be maintained when the recommended number of hosted files was reached) 550 (the number of connections that can be maintained when the recommended number of hosted files was reached)
Recommended Number of Hosted Files 50,000,000 (applies to files indexed or hosted by Synology Drive. For file access through other standard protocols, refer to the File Services section above) 50,000,000 (applies to files indexed or hosted by Synology Drive. For file access through other standard protocols, refer to the File Services section above)
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.
  • 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
Suggested Maximum Users 4,500 4,500
Suggested Concurrent Users 1,800 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
  • 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
Virtual Machine Manager
Recommended Virtual Machine Instances 8 (Learn more) 8 (Learn more)
Recommended Virtual DSM Number (Licenses required) 8 (including 1 Free License) 8 (including 1 Free License)
Notes The specifications vary depending on system configuration and memory size. The specifications vary depending on system configuration and memory size.
VPN Server
Maximum Connections 40 40
Hardware Specs
Hardware Specifications
CPU
CPU Model
DS1621+ AMD Ryzen_V1500B
DS1821+ AMD Ryzen_V1500B
CPU Quantity
DS1621+ 1
DS1821+ 1
CPU Core
DS1621+ 4
DS1821+ 4
CPU Architecture
DS1621+ 64-bit
DS1821+ 64-bit
CPU Frequency
DS1621+ 2.2 GHz
DS1821+ 2.2 GHz
Hardware Encryption Engine
DS1621+
DS1821+
Memory
System Memory
DS1621+ 4 GB DDR4 ECC SODIMM
DS1821+ 4 GB DDR4 ECC SODIMM
Memory Module Pre-installed
DS1621+ 4 GB (4 GB x 1)
DS1821+ 4 GB (4 GB x 1)
Total Memory Slots
DS1621+ 2
DS1821+ 2
Maximum Memory Capacity
DS1621+ 32 GB (16 GB x 2)
DS1821+ 32 GB (16 GB x 2)
Notes
DS1621+
  • 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.
DS1821+
  • 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
Drive Bays
DS1621+ 6
DS1821+ 8
Maximum Drive Bays with Expansion Unit
DS1621+ 16 (DX517 x 2)
DS1821+ 18 (DX517 x 2)
M.2 Drive Slots
DS1621+ 2 (NVMe)
DS1821+ 2 (NVMe)
Compatible Drive Type* (See all supported drives)
DS1621+
  • 3.5" SATA HDD
  • 2.5" SATA HDD
  • 2.5" SATA SSD
  • M.2 2280 NVMe SSD
DS1821+
  • 3.5" SATA HDD
  • 2.5" SATA HDD
  • 2.5" SATA SSD
  • M.2 2280 NVMe SSD
Hot Swappable Drive*
DS1621+
DS1821+
Notes
DS1621+
  • 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.
DS1821+
  • 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
RJ-45 1GbE LAN Port
DS1621+ 4 (with Link Aggregation / Failover support)
DS1821+ 4 (with Link Aggregation / Failover support)
USB 3.2 Gen 1 Port*
DS1621+ 3
DS1821+ 4
eSATA Port
DS1621+ 2
DS1821+ 2
Notes
DS1621+ The USB 3.0 standard was renamed to USB 3.2 Gen 1 by the USB Implementers Forum (USB-IF) in 2019.
DS1821+ 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
DS1621+ 1 x Gen3 x8 slot (x4 link)
DS1821+ 1 x Gen3 x8 slot (x4 link)
Appearance
Size (Height x Width x Depth)
DS1621+ 166 mm x 282 mm x 243 mm
DS1821+ 166 mm x 343 mm x 243 mm
Weight
DS1621+ 5.1 kg
DS1821+ 6 kg
Others
System Fan
DS1621+ 92 mm x 92 mm x 2 pcs
DS1821+ 120 mm x 120 mm x 2 pcs
Fan Speed Mode
DS1621+
  • Full-Speed Mode
  • Cool Mode
  • Quiet Mode
DS1821+
  • Full-Speed Mode
  • Cool Mode
  • Quiet Mode
Easy Replacement System Fan
DS1621+
DS1821+
Brightness Adjustable Front LED Indicators
DS1621+
DS1821+
Power Recovery
DS1621+
DS1821+
Noise Level*
DS1621+ 25.2 dB(A)
DS1821+ 22.2 dB(A)
Scheduled Power On / Off
DS1621+
DS1821+
Wake on LAN / WAN
DS1621+
DS1821+
Power Supply Unit / Adapter
DS1621+ 250 W
DS1821+ 250 W
AC Input Power Voltage
DS1621+ 100V to 240V AC
DS1821+ 100V to 240V AC
Power Frequency
DS1621+ 50/60 Hz, Single Phase
DS1821+ 50/60 Hz, Single Phase
Power Consumption
DS1621+ 51.22 W (Access)
25.27 W (HDD Hibernation)
DS1821+ 59.8 W (Access)
26.18 W (HDD Hibernation)
British Thermal Unit
DS1621+ 174.77 BTU/hr (Access)
86.22 BTU/hr (HDD Hibernation)
DS1821+ 204.05 BTU/hr (Access)
89.33 BTU/hr (HDD Hibernation)
Notes
DS1621+
  • 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%
DS1821+
  • 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
Operating Temperature
DS1621+ 0°C to 40°C (32°F to 104°F)
DS1821+ 0°C to 40°C (32°F to 104°F)
Storage Temperature
DS1621+ -20°C to 60°C (-5°F to 140°F)
DS1821+ -20°C to 60°C (-5°F to 140°F)
Relative Humidity
DS1621+ 5% to 95% RH
DS1821+ 5% to 95% RH
Certification
DS1621+
  • FCC
  • CE
  • BSMI
  • EAC
  • CCC
  • KC
  • VCCI
  • RCM
DS1821+
  • FCC
  • CE
  • BSMI
  • EAC
  • CCC
  • KC
  • VCCI
  • RCM
Warranty
DS1621+ 3-year hardware warranty, extendable to 5 years with EW201 or Extended Warranty Plus
DS1821+ 3-year hardware warranty, extendable to 5 years with EW201 or Extended Warranty Plus
Notes
DS1621+
  • 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. EW201/EW202 is only available in Asia, Africa, and Oceania. For exact availability information please visit their respective websites.
DS1821+
  • 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. EW201/EW202 is only available in Asia, Africa, and Oceania. For exact availability information please visit their respective websites.
Environment
DS1621+ RoHS Compliant
DS1821+ RoHS Compliant
Packaging Content
DS1621+
  • Main Unit X 1
  • Accessory Pack X 1
  • AC Power Cord X 1
  • RJ-45 LAN Cable X 2
  • Quick Installation Guide X 1
DS1821+
  • 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
DS1621+
DS1821+
Notes
DS1621+ All memory modules will operate at the maximum frequency specified by the CPU manufacturer.
DS1821+ All memory modules will operate at the maximum frequency specified by the CPU manufacturer.
Software Specs
DSM Specifications
Storage Management
Maximum Single Volume Size
DS1621+ 108 TB
DS1821+ 108 TB
Maximum Internal Volume Number
DS1621+ 64
DS1821+ 64
M.2 SSD Storage Pool Support*
DS1621+
DS1821+
SSD Read/Write Cache (Determining cache size)
DS1621+
DS1821+
SSD TRIM
DS1621+
DS1821+
Supported RAID Type
DS1621+
  • Synology Hybrid RAID
  • Basic
  • JBOD
  • RAID 0
  • RAID 1
  • RAID 5
  • RAID 6
  • RAID 10
DS1821+
  • Synology Hybrid RAID
  • Basic
  • JBOD
  • RAID 0
  • RAID 1
  • RAID 5
  • RAID 6
  • RAID 10
RAID Migration
DS1621+
  • Basic to RAID 1
  • Basic to RAID 5
  • RAID 1 to RAID 5
  • RAID 5 to RAID 6
DS1821+
  • Basic to RAID 1
  • Basic to RAID 5
  • RAID 1 to RAID 5
  • RAID 5 to RAID 6
Volume Expansion with Larger HDDs
DS1621+
  • Synology Hybrid RAID
  • RAID 1
  • RAID 5
  • RAID 6
  • RAID 10
DS1821+
  • Synology Hybrid RAID
  • RAID 1
  • RAID 5
  • RAID 6
  • RAID 10
Volume Expansion by Adding a HDD
DS1621+
  • Synology Hybrid RAID
  • JBOD
  • RAID 5
  • RAID 6
DS1821+
  • Synology Hybrid RAID
  • JBOD
  • RAID 5
  • RAID 6
Global Hot Spare Supported RAID Type
DS1621+
  • Synology Hybrid RAID
  • RAID 1
  • RAID 5
  • RAID 6
  • RAID 10
DS1821+
  • Synology Hybrid RAID
  • RAID 1
  • RAID 5
  • RAID 6
  • RAID 10
Notes
DS1621+
  • Creating M.2 storage pools requires the use of Synology-verified SSDs, which are rigorously tested under extreme temperature conditions. Thermal parameters for SSDs and NAS units are fine-tuned to ensure optimal management of thermal conditions under I/O-intensive environments. (Learn more)
  • Usable capacity for each volume will be lower than the maximum volume size and is dependent on the filesystem and the amount of system metadata stored.
  • Each internal volume (may consist of multiple drives) is expandable up to 108TB.
DS1821+
  • Creating M.2 storage pools requires the use of Synology-verified SSDs, which are rigorously tested under extreme temperature conditions. Thermal parameters for SSDs and NAS units are fine-tuned to ensure optimal management of thermal conditions under I/O-intensive environments. (Learn more)
  • Usable capacity for each volume will be lower than the maximum volume size and is dependent on the filesystem and the amount of system metadata stored.
  • Each internal volume (may consist of multiple drives) is expandable up to 108TB.
File System
Internal Drives
DS1621+
  • Btrfs
  • ext4
DS1821+
  • Btrfs
  • ext4
External Drives
DS1621+
  • Btrfs
  • ext4
  • ext3
  • FAT
  • NTFS
  • HFS+
  • exFAT
DS1821+
  • Btrfs
  • ext4
  • ext3
  • FAT
  • NTFS
  • HFS+
  • exFAT
Notes
DS1621+ exFAT Access can be installed for free from Package Center in DSM 7.0. In DSM 6.2 or earlier versions, exFAT Access needs to be purchased in Package Center.
DS1821+ exFAT Access can be installed for free from Package Center in DSM 7.0. In DSM 6.2 or earlier versions, exFAT Access needs to be purchased in Package Center.
File Services
File Protocol
DS1621+
  • SMB
  • AFP
  • NFS
  • FTP
  • WebDAV
  • Rsync
DS1821+
  • SMB
  • AFP
  • NFS
  • FTP
  • WebDAV
  • Rsync
Maximum Concurrent SMB/AFP/FTP Connections
DS1621+ 1,000
DS1821+ 1,000
Maximum Concurrent SMB/AFP/FTP Connections (with RAM expansion)
DS1621+ 2,000
DS1821+ 2,000
Windows Access Control List (ACL) Integration
DS1621+
DS1821+
NFS Kerberos Authentication
DS1621+
DS1821+
Notes
DS1621+
  • 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.
DS1821+
  • 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 & Shared Folder
Maximum Local User Accounts
DS1621+ 2,048
DS1821+ 2,048
Maximum Local Groups
DS1621+ 256
DS1821+ 256
Maximum Shared Folder
DS1621+ 512
DS1821+ 512
Maximum Shared Folder Sync Tasks
DS1621+ 16
DS1821+ 16
Hybrid Share
Maximum Hybrid Share Folders
DS1621+ 10
DS1821+ 10
Hyper Backup
Folder and Package Backup
DS1621+
DS1821+
Entire System Backup
DS1621+
DS1821+
Notes
DS1621+ Full-system backup requires DSM 7.2 or later.
DS1821+ Full-system backup requires DSM 7.2 or later.
High Availability
Synology High Availability
DS1621+
DS1821+
Log Center
DS1621+
DS1821+
Syslog Events per Second
DS1621+ 1,000
DS1821+ 1,000
Virtualization
VMware ESXi 6.5 and VAAI
DS1621+
DS1821+
Windows Server 2016
DS1621+
DS1821+
Windows Server 2019
DS1621+
DS1821+
Windows Server 2022
DS1621+
DS1821+
Citrix Ready
DS1621+
DS1821+
OpenStack
DS1621+
DS1821+
General Specifications
Supported Protocols
DS1621+ SMB1 (CIFS), SMB2, SMB3, NFSv3, NFSv4, NFSv4.1, NFS Kerberized sessions, iSCSI, HTTP, HTTPs, FTP, SNMP, LDAP, CalDAV
DS1821+ SMB1 (CIFS), SMB2, SMB3, NFSv3, NFSv4, NFSv4.1, NFS Kerberized sessions, iSCSI, HTTP, HTTPs, FTP, SNMP, LDAP, CalDAV
Supported Browsers
DS1621+
  • Chrome
  • Firefox
  • Edge
  • Safari
DS1821+
  • Chrome
  • Firefox
  • Edge
  • Safari
Supported Language
DS1621+ English, Deutsch, Français, Italiano, Español, Dansk, Norsk, Svenska, Nederlands, Русский, Polski, Magyar, Português do Brasil, Português Europeu, Türkçe, Český, ภาษาไทย, 日本語, 한국어, 繁體中文, 简体中文
DS1821+ English, Deutsch, Français, Italiano, Español, Dansk, Norsk, Svenska, Nederlands, Русский, Polski, Magyar, Português do Brasil, Português Europeu, Türkçe, Český, ภาษาไทย, 日本語, 한국어, 繁體中文, 简体中文
Notes
DS1621+ For an updated list of supported browser versions, check the DSM Technical Specifications.
DS1821+ For an updated list of supported browser versions, check the DSM Technical Specifications.
Add-on Packages view the complete package list
Antivirus by McAfee (Trial)
DS1621+
DS1821+
Central Management System
DS1621+
DS1821+
Synology Chat
DS1621+
DS1821+
Suggested Maximum Users
DS1621+ 1,500
DS1821+ 1,500
Suggested Concurrent Users
DS1621+ 150
DS1821+ 150
Notes
DS1621+ When applicable, systems are tested configured with maximum memory and set to allow the maximum number of connections.
DS1821+ When applicable, systems are tested configured with maximum memory and set to allow the maximum number of connections.
Download Station
DS1621+
DS1821+
Maximum Concurrent Download Tasks
DS1621+ 80
DS1821+ 80
SAN Manager
DS1621+
DS1821+
Maximum iSCSI Target Number
DS1621+ 128
DS1821+ 128
Maximum LUN
DS1621+ 256
DS1821+ 256
LUN Clone/Snapshot, Windows ODX
DS1621+
DS1821+
Notes
DS1621+ iSCSI Manager has been renamed to SAN Manager in DSM 7.0.
DS1821+ iSCSI Manager has been renamed to SAN Manager in DSM 7.0.
Synology MailPlus / MailPlus Server
DS1621+
DS1821+
Free Email Accounts
DS1621+ 5 (Additional accounts require purchase of licenses)
DS1821+ 5 (Additional accounts require purchase of licenses)
Suggested Maximum Users
DS1621+ 750
DS1821+ 750
Suggested Concurrent Users
DS1621+ 150
DS1821+ 150
Maximum Server Performance
DS1621+ 1,484,000 emails per day, approx. 45GB
DS1821+ 1,484,000 emails per day, approx. 45GB
Notes
DS1621+
  • 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).
DS1821+
  • 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
DS1621+
DS1821+
DLNA Compliance
DS1621+
DS1821+
Synology Photos
DS1621+
DS1821+
Facial Recognition
DS1621+
DS1821+
Object Recognition
DS1621+
DS1821+
Snapshot Replication
DS1621+
DS1821+
Maximum Snapshots per Shared Folder
DS1621+ 1,024
DS1821+ 1,024
Maximum of System Snapshots
DS1621+ 65,536
DS1821+ 65,536
Surveillance Station
DS1621+
DS1821+
Default Licenses
DS1621+ 2 (Additional cameras require purchase of licenses)
DS1821+ 2 (Additional cameras require purchase of licenses)
Suggested Maximum IP Cameras and Total FPS (H.264)
DS1621+
  • 720p: 40 channels, 1200 FPS
  • 1080p: 40 channels, 1050 FPS
  • 3M: 40 channels, 600 FPS
  • 5M: 40 channels, 440 FPS
  • 4K: 32 channels, 320 FPS
DS1821+
  • 720p: 40 channels, 1200 FPS
  • 1080p: 40 channels, 1050 FPS
  • 3M: 40 channels, 600 FPS
  • 5M: 40 channels, 440 FPS
  • 4K: 32 channels, 320 FPS
Suggested Maximum IP Cameras and Total FPS (H.265)
DS1621+
  • 720p: 40 channels, 1200 FPS
  • 1080p: 40 channels, 1200 FPS
  • 3M: 40 channels, 1120 FPS
  • 5M: 40 channels, 600 FPS
  • 4K: 40 channels, 480 FPS
DS1821+
  • 720p: 40 channels, 1200 FPS
  • 1080p: 40 channels, 1200 FPS
  • 3M: 40 channels, 1120 FPS
  • 5M: 40 channels, 600 FPS
  • 4K: 40 channels, 480 FPS
Notes
DS1621+
  • Performance figures are obtained from testing conducted with the device fully populated with drives, with their default memory configuration, and under a continuous recording setup. Actual system capabilities may vary based on configuration, drive performance, enabled features, and the presence of additional workloads.
  • Use NVR Selector to quickly find a suitable model based on your requirements.
  • The maximum number of camera stream outputs is 2 times the suggested maximum number of IP cameras.
DS1821+
  • Performance figures are obtained from testing conducted with the device fully populated with drives, with their default memory configuration, and under a continuous recording setup. Actual system capabilities may vary based on configuration, drive performance, enabled features, and the presence of additional workloads.
  • Use NVR Selector to quickly find a suitable model based on your requirements.
  • The maximum number of camera stream outputs is 2 times the suggested maximum number of IP cameras.
Synology Drive
DS1621+
DS1821+
Recommended Number of Concurrent Sync Clients
DS1621+ 550 (the number of connections that can be maintained when the recommended number of hosted files was reached)
DS1821+ 550 (the number of connections that can be maintained when the recommended number of hosted files was reached)
Recommended Number of Hosted Files
DS1621+ 50,000,000 (applies to files indexed or hosted by Synology Drive. For file access through other standard protocols, refer to the File Services section above)
DS1821+ 50,000,000 (applies to files indexed or hosted by Synology Drive. For file access through other standard protocols, refer to the File Services section above)
Notes
DS1621+
  • 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.
DS1821+
  • 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
DS1621+
DS1821+
Suggested Maximum Users
DS1621+ 4,500
DS1821+ 4,500
Suggested Concurrent Users
DS1621+ 1,800
DS1821+ 1,800
Notes
DS1621+
  • 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
DS1821+
  • 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
DS1621+
DS1821+
Virtual Machine Manager
DS1621+
DS1821+
Recommended Virtual Machine Instances
DS1621+ 8 (Learn more)
DS1821+ 8 (Learn more)
Recommended Virtual DSM Number (Licenses required)
DS1621+ 8 (including 1 Free License)
DS1821+ 8 (including 1 Free License)
Notes
DS1621+ The specifications vary depending on system configuration and memory size.
DS1821+ The specifications vary depending on system configuration and memory size.
VPN Server
DS1621+
DS1821+
Maximum Connections
DS1621+ 40
DS1821+ 40