Build a private cloud for your home

DS420j is a 4-bay desktop NAS designed for home data backup, file syncing, and sharing. Supporting up to 64 TB raw capacity, you can easily centralize all your multimedia collections.

Download Datasheet

CPU

64-bit 4-core 1.4 GHz

Performance

Over 112 MB/s encrypted reading and writing1

Storage

Maximum 64 TB raw capacity

Energy-saving

7.88 W in hibernation mode

Manage your photo collections

Organize your photos intelligently with Moments, a modern, AI-enabled photo management application that lets you effortlessly preserve your precious memories. Learn more

Stream content to your TV

Turn your Synology NAS into a home media hub and stream your digital contents to your favorite devices such as computers, mobile devices, Samsung TV, Apple TV, Google Chromecast, and DLNA devices.

Seamless integration with your mobile devices

Synology mobile applications are designed to allow quick and secure access to your data wherever you are.

Seamless integration with your mobile devices

Synology mobile applications are designed to allow quick and secure access to your data wherever you are.

Access and sync your files seamlessly

Synology Drive provides a built-in universal portal to access your data anytime and anywhere, and synchronize all your files across platforms, including Windows, macOS, Linux, Android, and iOS. Learn more

Sync files on demand: Save the storage space and network bandwidth of your PC.

Go back in time: Easily retrieve previous versions of your shared files.

Back up your data: Protect your files as scheduled or in real-time.

Reliable and efficient backup options

Synology Hyper Backup is a reliable and multi-directional backup solution offering data deduplication and compression. You can back up from various source folders, including external USB drives, another Synology NAS, rsync servers, or from public cloud services like Google Drive or Synology C2, and protect your data against malicious attacks and encryption-based ransomware threats. Learn more

Powered by Synology DSM

Multimedia

Complete multimedia solution for management, streaming, and playback.

Learn more

Desktop Backup

Simplified backup solution for your Mac, PC, and mobile devices.

Learn more

File Server/Management

Powerful built-in file management and sharing services.

Learn more

Synology Drive

A versatile solution for file management and synchronization. 

Learn more

Hyper Backup

Store multiple backup versions with block-level incremental data backup and cross-version deduplication.

Learn more

Surveillance Station

Complete surveillance solution for recording, monitoring, and management.

Learn more
  • 1 Status indicator
  • 2 LAN indicator
  • 3 Power button and indicator
  • 4 Drive status indicator
  • 5 1GbE RJ-45 port
  • 6 Power port
  • 7 Kensington Security Slot
  • 8 System fan
  • 9 USB 3.0 port
  • 10 Reset button

Notes:

  1. Performance figures may vary depending on environment, usage, and configuration.

Hardware Specifications

CPU

CPU

CPU Model Realtek RTD1296
CPU Quantity 1
CPU Architecture 64-bit
CPU Frequency 4-core 1.4 GHz
Hardware Encryption Engine

Memory

Memory

System Memory 1 GB DDR4 non-ECC
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.

Storage

Storage

Drive Bays 4
Compatible Drive Type* (See all supported drives)
  • 3.5" SATA HDD
  • 2.5" SATA HDD
  • 2.5" SATA SSD
Maximum Internal Raw Capacity 64 TB (16 TB drive x 4) (Capacity may vary by RAID types)
Maximum Single Volume Size* 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.
  • The maximum single volume size is not directly related to the maximum raw capacity. (Learn more)

External Ports

External Ports

RJ-45 1GbE LAN Port 1
USB 3.0 Port 2

File System

File System

Internal Drives
  • EXT4
External Drives
  • EXT4
  • EXT3
  • FAT
  • NTFS
  • HFS+
  • exFAT*
Notes exFAT Access is purchased separately in Package Center.

Appearance

Appearance

Size (Height x Width x Depth) 184 mm x 168 mm x 230 mm
Weight 2.21 kg

Others

Others

System Fan 80 mm x 80 mm x 2 pcs
Fan Speed Mode
  • Full-Speed Mode
  • Cool Mode
  • Quiet Mode
  • Low-power Mode
Brightness Adjustable Front LED Indicators
Power Recovery
Noise Level* 20.6 dB(A)
Scheduled Power On / Off
Wake on LAN / WAN
Power Supply Unit / Adapter 90 W
AC Input Power Voltage 100 V to 240 V AC
Power Frequency 50/60 Hz, Single Phase
Power Consumption* 21.71 W (Access)
7.88 W (HDD Hibernation)
British Thermal Unit 74.08 BTU/hr (Access)
26.89 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
  • EAC
  • BSMI
  • VCCI
  • CCC
  • RCM

Warranty

Warranty

2 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 Adapter X 1
  • AC Power Cord X 1
  • RJ-45 LAN Cable X 1
  • Quick Installation Guide X 1

Optional Accessories

Optional Accessories

DSM Specifications

Storage Management

Storage Management

Maximum Internal Volume Number 64
Maximum iSCSI Target Number 10
Maximum iSCSI LUN 10
SSD TRIM
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
Global Hot Spare Supported RAID Type
  • Synology Hybrid RAID
  • RAID 1
  • RAID 5

File Services

File Services

File Protocol CIFS/AFP/NFS/FTP/WebDAV
Maximum Concurrent CIFS/AFP/FTP Connections 100
Windows Access Control List (ACL) Integration
NFS Kerberos Authentication

Account & Shared Folder

Account & Shared Folder

Maximum Local User Accounts 1,024
Maximum Local Groups 256
Maximum Shared Folder 256
Maximum Shared Folder Sync Tasks 4

Log Center

Log Center

Syslog Events per Second 100

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
  • Chrome
  • Firefox
  • Edge
  • Internet Explorer 10 onwards
  • Safari 10 onwards
  • Safari (iOS 10 onwards)
  • Chrome (Android 6.0 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

Synology Chat

Synology Chat

Maximum Users 10
Notes
  • The number of concurrent HTTP connections for Synology Chat was configured to the maximum.
  • CPU and RAM usage were both under 80% when the number of maximum users was reached.

Download Station

Download Station

Maximum Concurrent Download Tasks 80

exFAT Access (Optional)

exFAT Access (Optional)

Media Server

Media Server

DLNA Compliance

Moments

Moments

Facial Recognition
Subject Recognition

Surveillance Station

Surveillance Station

Maximum IP cam (Licenses required) 16 (including 2 Free License) (See All Supported IP Cameras)
Total FPS (H.264) 480 FPS @ 720p (1280x720)
288 FPS @ 1080p (1920x1080)
150 FPS @ 3M (2048x1536)
100 FPS @ 5M (2591x1944)
70 FPS @ 4K (3840x2160)
Total FPS (H.265) 480 FPS @ 720p (1280x720)
384 FPS @ 1080p (1920x1080)
256 FPS @ 3M (2048x1536)
160 FPS @ 5M (2591x1944)
100 FPS @ 4K (3840x2160)
Total FPS (MJPEG) 240 FPS @ 720p (1280x720)
150 FPS @ 1080p (1920x1080)
100 FPS @ 3M (2048x1536)
60 FPS @ 5M (2591x1944)
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 100,000 (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 200 (the number of connections that can be maintained when the recommended number of hosted files was reached)
Notes
  • Exceeding the limits above may result in longer response time in file operations.
  • EXT4 file system and non-encrypted shared folders were used during the aforementioned testing.

Synology Office

Synology Office

Maximum Users 200
Notes
  • Multiple files were opened for testing and each file was edited by 30 users simultaneously.
  • CPU and RAM usage were both under 80% when the number of maximum users was reached.
  • Client performance may affect maximum simultaneous editing users. Client PCs used for testing: Intel Core i3-3220 / 8GB RAM

Video Station

Video Station

Video Transcoding Group 2 (See more)

VPN Server

VPN Server

Maximum Connections 10

Notes:

  • Model specifications are subject to change without prior notice.
  • The figures are based on Synology internal testing. No other services or applications are processed during the performance tests.