SYNOLOGY DISKSTATION DS425+ 4 BAY NAS

Maximum Single Volume Size: 108TB

Maximum Internal Volume Number: 32

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

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

Notes:

Each internal volume (may consist of multiple drives) is expandable up to 108TB.

Actual maximum storage pool and volume sizes vary depending on drives used, the number of drive bays available, and the RAID configuration.

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.

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)

Internal Drives: Btrfs, ext4

External Drives: Btrfs, ext4, ext3, FAT32, NTFS, HFS+, exFAT

File Protocol: SMB, AFP, NFS, FTP, WebDAV, Rsync

Maximum Number of SMB Connections (FSCT-Based): 10

Windows Access Control List (ACL) Integration: ✔

NFS Kerberos Authentication: ✔

Notes:

Connection value of this model is tested with Synology SATA HDD fully populated and all onboard network ports

Models with expandable memory are tested with the maximum supported quantity installed.

SMB performance was evaluated using Microsoft File Server Capacity Tool (FSCT) version 1.3, with the following configuration:

Test workload: HomeFolder scenario provided by the FSCT tool

Test duration: 600 seconds

Domain controller & FSCT controller: Windows Server 2022

FSCT clients: 8 × Windows 10 machines

SMB feature: Directory leasing enabled

Folder and Package Backup: ✔

Entire System Backup: ✔

 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

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, HTTP, HTTPs, FTP, SNMP, LDAP, CalDAV

Supported Browsers: 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

Notes: For an updated list of supported browser versions, check the DSM Technical Specifications.

Maximum Number of Users: 100

Notes: 

Measured with simulated users, each with an average record of 20,000 messages, emojis, or stickers. The required server response time is below ten seconds.

Models with expandable memory are tested with the maximum supported quantity installed.

Maximum iSCSI Target Number: 2

Maximum LUN: 4

LUN Clone/Snapshot, Windows ODX: ✔

Free Email Accounts: 5 (Additional accounts require purchase of licenses)

Maximum Number of Users: 20

Notes:

The suggested maximum number of users is based on the following workload: 20% of users with a 20,000 item mailbox randomly performing actions and receiving 240 emails per day, and 80% of users receiving 20 emails per day. Learn more

Models with SSD support are tested with a single SSD volume.

Models with expandable memory are tested with the maximum supported quantity installed. Learn more about memory requirements.

Operating in high-availability mode will incur additional overhead.

Features enabled during evaluation: anti-spam, anti-virus, DNSBL, greylist, content scanning, and full-text search (English).

Facial Recognition: ✔

Object Recognition: ✔

Notes: Object recognition requires an upgrade of memory capacity to a minimum of 4 GB.

Maximum Snapshots per Shared Folder: 128

Maximum Snapshots per LUN: 32

Maximum Snapshots per System: 1,024

Maximum Replication Tasks for Shared Folders: 16

Maximum Replication Tasks for LUNs: 8

Maximum Replication Tasks per System: 16

Default Licenses: 2(Additional cameras require purchase of licenses)

Maximum IP Cameras and Total FPS (H.264): 

1080p: 40 channels, 800 FPS

3M: 35 channels, 350 FPS

5M: 28 channels, 280 FPS

4K: 17 channels, 170 FPS

Maximum IP Cameras and Total FPS (H.265):

1080p: 40 channels, 1200 FPS

3M: 40 channels, 600 FPS

5M: 40 channels, 480 FPS

4K: 20 channels, 200 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 number of video channels that can be viewed simultaneously is double the maximum number of cameras for the same codec and resolution.

Maximum Number of Users: 20

Maximum Number of Hosted Files: 500,000 (applies to files indexed or hosted by Synology Drive. For file access through other standard protocols, refer to the File Services section above)

Notes:

The suggested maximum number of users is based on the following workload: 20% of users randomly perform file operations (upload, download, move, and delete), and 80% of users are logged in but idle. Learn more

Models with SSD support are tested with a single SSD volume.

Models with expandable memory are tested with the maximum supported quantity installed.

Exceeding the recommended numbers above will not block application operations, but may result in longer response time.

Btrfs file system and non-encrypted shared folders were used during the aforementioned testing.

Maximum Number of Users: 20

Notes: 

The suggested maximum number of users is based on the following workload: 20% of users are executing random actions at an average of 30-second intervals, and 80% of users are logged in and viewing a file. Learn more

Models with SSD support are tested with a single SSD volume.

Models with expandable memory are tested with the maximum supported quantity installed.

Client performance may affect maximum simultaneous editing users. Client PCs used for testing: Intel Core i3-3220 / 8GB RAM

Recommended Virtual Machine Instances: 2

(Learn more)

Recommended Virtual DSM Number (Licenses required): 2 (including 1 Free License)

Notes: The specifications vary depending on system configcuration and memory size

CPU Model: Intel Celeron J4125

CPU Quantity: 1

CPU Cores: 4

CPU Threads: 4

CPU Architecture: 64-bit

CPU Frequency: 2.0 (base) / 2.7 (turbo) GHz

Hardware Encryption Engine: ✔

System Memory: 2 GB DDR4 non-ECC

Total Memory Slots: 1

Maximum Memory Capacity: 6 GB (2 GB + 4 GB)

Notes: 

Synology may revise pre-installed memory module specifications in response to component lifecycle and supply conditions. All revised components undergo the same rigorous validation to ensure equivalent compatibility, stability, and 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.

Drive Bays: 4

M.2 Drive Slots: 2 (NVMe)

Drive Type (See all supported drives): 

3.5" 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.

Synology only guarantees full functionality, reliability, and performance for compatible drives. Please consult our compatibility list before purchasing hard drives. For more details, please refer to this article.

RJ-45 1GbE LAN Port: 1

RJ-45 2.5GbE LAN Port: 1

USB 3.2 Gen 1 Port: 2

Notes: MTU value of 1GbE LAN port has a limit of 1500.

Size (Height x Width x Depth): 166 mm x 199 mm x 223 mm

Weight: 2.18KG

System Fan: 92 mm x 92 mm x 2 pcs

Fan Speed Mode: 

Full-Speed Mode

Cool Mode

Quiet Mode

Brightness Adjustable Front LED Indicators: ✔

Power Recovery: ✔

Noise Level*: 21.6 dB(A)

Scheduled Power On / Off:  ✔

Wake on LAN / WAN: ✔

Power Supply Unit / Adapter:  90 WATTS

AC Input Power Voltage: 100V to 240V AC

Power Frequency: 50/60 Hz, Single Phase

Power Consumption: 28.25 watts (Access)
6.10 watts (HDD Hibernation)

British Thermal Unit: 96.33 BTU/hr (Access)
20.79 BTU/hr (HDD Hibernation)

Notes: 

For more information on how power consumption is measured, refer to this article.

Noise testing was conducted with the Synology system fully installed with Synology SATA SSDs and in an idle state. Two GRAS 40AE microphones were placed at a 1 m distance from the front and rear of the device. Background noise: 16.49-17.51 dB(A); Temperature: 24.25-25.75˚C; Humidity: 58.2-61.8%.

Operating Temperature: 0°C to 40°C (32°F to 104°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

FCC

CE

BSMI

VCCI

RCM

UKCA

EAC

CCC

KC

BIS

Main Unit X 1

Accessory Pack X 1

AC Power Adapter X 1

AC Power Cord X 1

RJ-45 LAN Cable X 2