DiskStation DS1621xs+

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DiskStation DS1621xs+

On-premises cloud solution built for performance

Features
Specs

High-end scalable NAS in desktop form factor

DS1621xs+ is a high-end NAS with server-class performance in a 6-bay desktop form factor. The built-in M.2 SSD cache slots, 10GbE port, expandable memory, and scalable storage design allow you to boost the performance of your NAS, making it ideal for small and medium-sized businesses that need an efficient and space-saving storage solution.

Download Datasheet

CPU

Intel^® Xeon D-1527 4-core 2.2 GHz

Memory

8 GB DDR4 ECC SODIMM, up to 32 GB

High Performance

Over 3,100 MB/s sequential read

Scalability

Up to 16 drives with DX517¹

Supercharge your storage with speedy performance

DS1621xs+ comes with built-in M.2 SSD cache slots capable of providing I/O response speeds 20 times faster than hard drives without occupying front drive bays. The built-in 10GbE port provides fast data transmission and can be bonded with an additional network interface card for higher network bandwidth.

M.2 SSD support

Dual M.2 2280 SSD supporting NVMe SSDs
10GbE support

Built-in 10GBASE-T for bandwidth intensive environments

5-year warranty

At Synology, we are committed to product innovation and quality. Synology guarantees a robust and reliable data management experience with a 5-year limited warranty, providing responsive technical support and hardware replacement services to maximize your return on investment.

Ultimate Backup Solution

DS1621xs+ 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

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

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
Microsoft 365 / Google Workspace

Protect corporate data stored on the cloud. On-premise backup solution with a centralized dashboard. Optimize storage efficiency with single instancing and block-level deduplication technology.
Microsoft 365 Google Workspace

Virtual Machine Manager

Sandbox new software , manage resources using a single interface, and increase deployment flexibility with Synology Virtual Machine Manager. Run Windows, Linux, and Virtual DSM instances on your Synology NAS in just a few steps. Learn more

Snapshots for virtual machines

Clone and restore complete virtual machines within seconds.

Live migration

Seamlessly migrate virtual machines from one Synology NAS to another.

Multi-tenant environment

Create multiple isolated virtual machines for business units or departments.

Powered by Synology DiskStation Manager

Central Management System

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

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Synology MailPlus

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

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Synology High Availability

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

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Security

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

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Synology Drive

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

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Surveillance Station

Complete surveillance solution for recording, monitoring, and management.

Learn more

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 3.0 port

9 System fan
10 Power port
11 Kensington Security Slot
12 10GbE RJ-45 port

13 1GbE RJ-45 port
14 Reset button
15 Expansion port
16 PCIe expansion slot

Notes:

DS1621xs+ can be scaled up to 16 drives with 2 x DX517. Synology expansion units are sold separately.

Hardware Specs
Software Specs

Hardware Specifications
CPU
CPU	CPU Model	Intel Xeon D-1527
	CPU Quantity	1
	CPU Architecture	64-bit
	CPU Frequency	4-core 2.2 (base) / 2.7 (turbo) GHz
	Hardware Encryption Engine (AES-NI)
Memory
Memory	System Memory	8 GB DDR4 ECC SODIMM
	Memory Module Pre-installed	8 GB (8 GB x 1)
	Total Memory Slots	2
	Maximum Memory Capacity	32 GB (16 GB x 2)
	Notes	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 on the recommended memory configurations, visit here. 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.
Storage
Storage	Drive Bays	6
	Maximum Drive Bays with Expansion Unit	16 (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
	Maximum Single Volume Size*	200 TB (32 GB memory required) 108 TB
	Hot Swappable Drive
	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 108 TB (with memory less than 32 GB) or 200 TB (with memory equal to or greater than 32 GB).
External Ports
External Ports	RJ-45 1GbE LAN Port	2 (with Link Aggregation / Failover support)
	RJ-45 10GbE LAN Port	1
	USB 3.2 Gen 1 Port*	3
	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 (x8 link)
File System
File System	Internal Drives	Btrfs EXT4
	External Drives	Btrfs EXT4 EXT3 FAT NTFS HFS+ exFAT*
	Notes	exFAT Access is purchased separately in Package Center.
Appearance
Appearance	Size (Height x Width x Depth)	166 mm x 282 mm x 243 mm
	Weight	5.3 kg
Others
Others	System Fan	92 mm x 92 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*	25.2 dB(A)
	Scheduled Power On / Off
	Wake on LAN / WAN
	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*	62.85 W (Access) 34.26 W (HDD Hibernation)
	British Thermal Unit	214.45 BTU/hr (Access) 116.89 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	5 Years
	Notes	The warranty period starts from the purchase date as stated on your purchase receipt. (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	DDR4 ECC SODIMM: D4ES01-8G DDR4 ECC SODIMM: 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
Storage Management	Maximum Internal Volume Number	256
	SSD Read / Write Cache (White Paper)
	SSD TRIM
	RAID Group
	Supported RAID Type	RAID F1 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	RAID F1 RAID 1 RAID 5 RAID 6 RAID 10
	Volume Expansion by Adding a HDD	RAID F1 JBOD RAID 5 RAID 6
	Global Hot Spare Supported RAID Type	RAID F1 RAID 1 RAID 5 RAID 6 RAID 10
File Services
File Services	File Protocol	SMB/AFP/NFS/FTP/WebDAV
	Maximum Concurrent SMB/AFP/FTP Connections	2,000
	Maximum Concurrent SMB/AFP/FTP Connections (with RAM expansion)	8,000
	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. During testing, the maximum number of SSDs supported by this model is installed in a RAID 5 configuration. 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
Account & Shared Folder	Maximum Local User Accounts	16,000
	Maximum Local Groups	512
	Maximum Shared Folder	512
	Maximum Shared Folder Sync Tasks	32
High Availability
High Availability	Synology High Availability
Log Center
Log Center
	Syslog Events per Second	1,500
Virtualization
Virtualization	VMware vSphere with VAAI
	Windows Server 2016
	Windows Server 2019
	Citrix Ready
	OpenStack
General Specifications
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 11 onwards Safari 13 onwards Safari (iOS 13.0 onwards) Google Chrome (Android 11.0 onwards)
	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
Add-on Packages view the complete package list
Antivirus by McAfee (Trial)
Antivirus by McAfee (Trial)
Central Management System
Central Management System
Synology Chat
Synology Chat
	Maximum Users	4,000
	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
Document Viewer
Download Station
Download Station
	Maximum Concurrent Download Tasks	80
exFAT Access (Optional)
exFAT Access (Optional)
iSCSI Manager
iSCSI Manager	Maximum iSCSI Target Number	256
	Maximum iSCSI LUN	512
	iSCSI LUN Clone/Snapshot, Windows ODX
Synology MailPlus / MailPlus Server
Synology MailPlus / MailPlus Server
	Free Email Accounts	5 (Licenses required for additional accounts)
	Maximum Number of Concurrent Users	450
	Maximum Server Performance	3,363,000 emails per day, approx. 102GB
	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
Media Server
	DLNA Compliance
Moments
Moments
	Facial Recognition
	Subject Recognition
	Auto Color & Rotate
	Moments Select
Snapshot Replication
Snapshot Replication
	Maximum Snapshots per Shared Folder	1,024
	Maximum of System Snapshots	65,536
Surveillance Station
Surveillance Station
	Maximum IP cam (Licenses required)	75 (including 2 Free License) (See All Supported IP Cameras)
	Total FPS (H.264)	2250 FPS @ 720p (1280x720) 1050 FPS @ 1080p (1920x1080) 600 FPS @ 3M (2048x1536) 400 FPS @ 5M (2591x1944) 280 FPS @ 4K (3840x2160)
	Total FPS (H.265)	2250 FPS @ 720p (1280x720) 2250 FPS @ 1080p (1920x1080) 1125 FPS @ 3M (2048x1536) 700 FPS @ 5M (2591x1944) 490 FPS @ 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
Synology Drive
	Recommended Number of Hosted Files	3,000,000 (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	900 (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
Synology Office
	Maximum Users	2,900
	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
Video Station
Virtual Machine Manager
Virtual Machine Manager
	Recommended Virtual Machine Instances	8 (Learn more)
	Recommended Virtual DSM Number (Licenses required)	8 (including 1 Free License)
	Notes	The specifications vary depending on system configuration and memory size.
VPN Server
VPN Server
	Maximum Connections	40

Notes:

Model specifications are subject to change without prior notice.
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.
The actual performance may be lower than lab testing figure due to differences in server configuration, deployment, and the number of active operations.
If usage requirements exceed the specifications above, please contact our regional partners for professional advice.