DiskStation DS425+

A compact storage hub with 100% data ownership

Conquer data chaos

The DS425+ features built-in 2.5GbE networking and supports both SATA SSDs and HDDs in 2.5″/3.5″ internal bays, as well as M.2 NVMe drives via M.2 slots for use cache.1,5

Compact 4-bay

Up to 80 TB of raw storage1,2

Speedy storage

Built-in 2.5GbE port and over 278/281 MB/s sequential read/write3

Versatile applications

Back up multiple endpoints, manage 40 IP cameras4, or safely sync and share files across sites

CPU	CPU Model	Intel Celeron J4125
	CPU Quantity	1
	CPU Core	4
	CPU Architecture	64-bit
	CPU Frequency	2.0 (base) / 2.7 (turbo) GHz
	Hardware Encryption Engine
Memory	System Memory	2 GB DDR4 non-ECC
	Total Memory Slots	1
	Maximum Memory Capacity	6 GB (2 GB + 4 GB)
	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.
Storage	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. Compatible drives are mandatory. Please consult our compatibility list before purchasing hard drives. For more details, please refer to this article.
External Ports	RJ-45 1GbE LAN Port	1
	RJ-45 2.5GbE LAN Port	1
	USB 3.2 Gen 1 Port	2
	Notes	This device’s 1GbE LAN ports have a maximum transmission unit (MTU) size of 1,500 bytes.
Appearance	Size (Height x Width x Depth)	166 mm x 199 mm x 223 mm
	Weight	2.18 kg
Others	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 G.R.A.S. type 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%.
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)
	Operating Humidity	8% to 80% RH
	Storage Humidity	5% to 95% RH
Certification	FCC CE BSMI VCCI RCM UKCA EAC CCC KC BIS
Warranty	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.
Environment	RoHS Compliant
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 2
Optional Accessories	DDR4 non-ECC SODIMM: D4NS01-4G Enterprise Series 3.5″ SATA HDD: HAT5300 Series Plus Series 3.5″ SATA HDD: HAT3300 Series Enterprise Series 2.5″ SATA SSD: SAT5200 Series Enterprise Series M.2 2280 NVMe SSD: SNV3400 & SNV5400 Series

DSM Specifications
Storage Management	Maximum Single Volume Size	108 TB
	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 depend on drive sizes 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)
File System	Internal Drives	Btrfs ext4
	External Drives	Btrfs ext4 ext3 FAT32 NTFS HFS+ exFAT
File Services	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
Account & Shared Folder	Maximum Local User Accounts	512
	Maximum Local Groups	128
	Maximum Shared Folder	128
	Maximum Shared Folder Sync Tasks	4
Hybrid Share	Maximum Hybrid Share Folders	10
Hyper Backup	Folder and Package Backup
	Entire System Backup
High Availability	Synology High Availability
Log Center	Syslog Events per Second	800
Virtualization	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
General Specifications	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.
Add-on Packages view the complete package list
Central Management System
Synology AI Console	Third-Party AI Model Integration
Synology Chat	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.
Download Station	Maximum Concurrent Download Tasks	80
SAN Manager	Maximum iSCSI Target Number	2
	Maximum LUN	4
	LUN Clone/Snapshot, Windows ODX
Synology MailPlus / MailPlus Server	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).
Media Server	DLNA Compliance
Synology Photos	Facial Recognition
	Object Recognition
	Notes	Object recognition requires an upgrade of memory capacity to a minimum of 4 GB.
Snapshot Replication	Maximum Snapshots per Shared Folder	128
	Maximum of System Snapshots	1,024
Surveillance Station	Default Licenses	2 (Additional cameras require purchase of licenses)
	Suggested 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
	Suggested 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 streams that can be viewed simultaneously is twice the suggested maximum number of cameras. For example, if the suggested maximum number of cameras for a model is 10 under H.264, 1080p, the model can support up to 20 streams of the same specification at the same time.
Synology Drive	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.
Synology Office	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
Virtual Machine Manager	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 configuration and memory size.
VPN Server	Maximum Connections	4