Powered by Synology DiskStation Manager
The RS3621xs+ runs Synology DiskStation Manager (DSM), the web-based operating system with applications and services designed specifically for businesses.
High-performance enterprise storage built for data accuracy and security.
The RS3621xs+ keeps your data protected while you concentrate on delivering the best results to your customers — even when disaster strikes.
Dual PSUs provide protection against a PSU failure or accidental cord removal while hot-swappable fans allow them to be replaced without powering down the system.
Synology High Availability (SHA) pairs two identical units together creating an active-passive cluster with minute-level failover. Learn more
Btrfs prevents data corruption and reduces maintenance overheads with advanced storage technologies and optimized snapshots. Learn more

A comprehensive backup and recovery solution for securing data stored on Synology servers. Backup data locally, to another Synology device, rsync server, or cloud-based storage such as Google Drive, Dropbox, S3-compatible destinations, and Synology C2. Deduplication
Easily schedule flexible point-in-time backups of shared folders and iSCSI LUNs with an RPO as low as 5 minutes and recovery in seconds. Set up replication and failover to other Synology storage systems for fast RTOs and minimal service disruption. Learn more
Enables administrators to easily backup the entire IT infrastructure to their NAS, including Windows & Linux workstations and servers, file servers, VMware and Hyper-V virtual machines, and Microsoft 365 and Google Workspace accounts. Backups benefit from deduplication, multiversioning, and optimizations to reduce bandwidth and storage used. Learn more
Synology Surveillance Station transforms the RS3621xs+ into a feature-packed Network Video Recorder solution. Support for up to 90 IP cameras
AES-256 encryption adds additional security to the locally-stored footage.
Access recordings and live streams whenever you want using a web browser, desktop client, or the DS cam mobile app.
Email, SMS, or push notifications alert you when incidents occur or predefined conditions are met.

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



The RS3621xs+ runs Synology DiskStation Manager (DSM), the web-based operating system with applications and services designed specifically for businesses.
Conveniently manage your fleet of Synology NAS from a centralized console.
Instantly access your NAS files across multiple devices whenever you want, wherever you are.
Satisfy all team collaboration needs behind the safety of your own private cloud with Synology Office, Calendar, and Chat.
Run various operating systems in isolated sandboxes. Seamlessly clone, store, and migrate virtual machines.
Shield your Synology NAS from the most sophisticated threats with industry-leading security solutions.
Back up and synchronize data easily between public cloud accounts and your NAS.
At Synology, we are committed to product innovation and quality. The RS3621xs+ is backed by a 5-year limited warranty that includes technical support and hardware replacement services to maximize your return on investment. Learn more
Hardware Specifications |
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CPU |
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CPU
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CPU Model | Intel Xeon D-1541 |
| CPU Quantity | 1 | |
| CPU Core | 8 | |
| CPU Architecture | 64-bit | |
| CPU Frequency | 2.1 (base) / 2.7 (turbo) GHz | |
| Hardware Encryption Engine | ||
Memory |
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Memory
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System Memory | 8 GB DDR4 ECC UDIMM |
| Memory Module Pre-installed | 8 GB (8 GB x 1) | |
| Total Memory Slots | 4 | |
| Maximum Memory Capacity | 64 GB (16 GB x 4) | |
| Notes |
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Storage |
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Storage
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Drive Bays | 12 |
| Maximum Drive Bays with Expansion Unit | 36 (RX1217 x 2) | |
| Drive Type (See all supported drives) |
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| Hot Swappable Drive* | ||
| Notes | Synology only guarantees full functionality, reliability, and performance for Synology drives listed on the compatibility list. The use of non-validated components may limit certain functionality and result in data loss and system instability. | |
External Ports |
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External Ports
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RJ-45 1GbE LAN Port | 4 |
| RJ-45 10GbE LAN Port | 2 | |
| USB 3.2 Gen 1 Port | 2 | |
| Expansion Port | 2 | |
| Expansion Port Type | Infiniband | |
PCIe |
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PCIe
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PCIe Expansion | 2 x Gen3 x8 slots (x8 link) |
Appearance |
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Appearance
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Form Factor (RU) | 2U |
| Size (Height x Width x Depth) | 88 mm x 482 mm x 724 mm | |
| Weight | 14.5 kg | |
| Rack Installation Support* | 4-post 19" rack (Synology Rail Kit - RKS-02) | |
| Notes | The rail kit is sold separately | |
Others |
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Others
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System Fan | 80 mm x 80 mm x 4 pcs |
| Fan Speed Mode |
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| Easy Replacement System Fan | ||
| Power Recovery | ||
| Noise Level* | 50.2 dB(A) | |
| Scheduled Power On / Off | ||
| Wake on LAN / WAN | ||
| Power Supply Unit / Adapter |
500 watts 550 watts* |
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| Redundant Power Supply | ||
| AC Input Power Voltage | 100 V to 240 V AC | |
| Power Frequency | 50/60 Hz, Single Phase | |
| Power Consumption* |
142.5 watts (Access) 72.76 watts (HDD Hibernation) |
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| British Thermal Unit |
485.93 BTU/hr (Access) 248.11 BTU/hr (HDD Hibernation) |
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| Notes |
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Temperature |
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Temperature
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Operating Temperature | 0°C to 35°C (32°F to 95°F) |
| Storage Temperature | -20°C to 60°C (-5°F to 140°F) | |
| Operating Humidity | 8% to 80% RH | |
| Storage Humidity | 5% to 95% RH | |
Certification |
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Certification
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Warranty |
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Warranty
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5 Years | |
| Notes | The warranty period starts from the purchase date as stated on your purchase receipt. (Learn more) | |
Environment |
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Environment
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RoHS Compliant | |
Packaging Content |
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Packaging Content
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Optional Accessories |
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Optional Accessories
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| Notes | All memory modules will operate at the maximum frequency specified by the CPU manufacturer. | |
DSM Specifications |
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| Maximum Single Volume Size |
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| Maximum Internal Volume Number | 256 | |
| SSD Read/Write Cache (Determining cache size) | ||
| SSD TRIM | ||
| RAID Group | ||
| Supported RAID Type |
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| RAID Migration |
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| Volume Expansion with Larger HDDs |
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| Volume Expansion by Adding a HDD |
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| Global Hot Spare Supported RAID Type |
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| Notes |
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| Internal Drives |
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| External Drives |
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| File Protocol |
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| Maximum Number of SMB Connections (FSCT-Based) | 1,300 | |
| Windows Access Control List (ACL) Integration | ||
| NFS Kerberos Authentication | ||
| Notes |
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| Maximum Local User Accounts | 5,120 | |
| Maximum Local Groups | 512 | |
| Maximum Shared Folder | 512 | |
| Maximum Shared Folder Sync Tasks | 32 | |
| Maximum Hybrid Share Folders | 15 | |
| Folder and Package Backup | ||
| Entire System Backup | ||
| Notes | Full-system backup requires DSM 7.2 or later. | |
| Synology High Availability | ||
| Syslog Events per Second | 3,000 | |
Virtualization |
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Virtualization
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VMware vSphere | ESXi 8.0 U2, ESXi 8.0 U1, ESXi 8.0, ESXi 7.0 U3, ESXi 7.0 U2, ESXi 7.0 U1, ESXi 7.0, ESXi 6.7 U3, ESXi 6.7 U2, ESXi 6.7 U1, ESXi 6.7, ESXi 6.5 U3, ESXi 6.5 U2, ESXi 6.5 U1, ESXi 6.5 |
| Microsoft Hyper-V | Windows Server 2022, Windows Server 2019, Windows Server 2016 | |
| Citrix XenServer | XenServer 8, Citrix Hypervisor 8.2 LTSR CU1 | |
| OpenStack | Cinder | |
| Supported Protocols | SMB1 (CIFS), SMB2, SMB3, NFSv3, NFSv4, NFSv4.1, NFS Kerberized sessions, iSCSI, Fibre Channel, HTTP, HTTPs, FTP, SNMP, LDAP, CalDAV | |
| Supported Browsers |
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| 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 | |
| Notes | For an updated list of supported browser versions, check the DSM Technical Specifications. | |
Add-on Packages view the complete package list |
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Synology AI Console |
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Synology AI Console
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Synology AI Console
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Third-Party AI Model Integration | |
| Maximum De-Identification Rate | 1,300 words per second | |
| Notes |
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| Maximum Number of Users | 500 | |
| Notes |
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Download Station |
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Download Station
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Download Station
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Maximum Concurrent Download Tasks | 80 |
| Maximum iSCSI Target Number | 128 | |
| Maximum LUN | 256 | |
| LUN Clone/Snapshot, Windows ODX | ||
| Free Email Accounts | 5 (Additional accounts require purchase of licenses) | |
| Maximum Number of Users | 2,800 | |
| Notes |
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| DLNA Compliance | ||
| Facial Recognition | ||
| Object Recognition | ||
| Maximum Snapshots per Shared Folder | 512 | |
| Maximum Snapshots per LUN | 128 | |
| Maximum Snapshots per System | 16,384 | |
| Maximum Replication Tasks for Shared Folders | 64 | |
| Maximum Replication Tasks for LUNs | 32 | |
| Maximum Replication Tasks per System | 64 | |
| Default Licenses | 2 (Additional cameras require purchase of licenses) | |
| Maximum IP Cameras and Total FPS (H.264) |
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| Maximum IP Cameras and Total FPS (H.265) |
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| Notes |
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| Maximum Number of Users | 2,400 | |
| Maximum Number of Hosted Files | 15,000,000 (applies to files indexed or hosted by Synology Drive. For file access through other standard protocols, refer to the File Services section above) | |
| Notes |
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| Maximum Number of Users | 2,300 | |
| Notes |
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| Recommended Virtual Machine Instances | 16 (Learn more) | |
| Recommended Virtual DSM Number (Licenses required) | 16 (including 1 Free License) | |
| Notes | The specifications vary depending on system configuration and memory size. | |
| Maximum Connections | 32 | |

4.7 / 5Synology is recognized in the Gartner Peer Insights Voice of the Customer for Primary Storage Platform.