Intended for home-office and small-office data sharing, surveillance center management, and data backups, the Synology DiskStation DS425+ is a four-bay network-attached storage (NAS) device that provides solid performance in a desktop form factor. It offers tool-free drive sleds, a pair of M.2 SSD slots for fast caching or flash storage, and the excellent DSM operating system from Synology, a multi-year Readers' Choice award-winning brand. It’s a strong performer, and its $519.99 price is reasonable. However, you can only use Synology-branded M.2 SSDs in this NAS. If you need more ports and want third-party options for M.2 SSDs, we recommend our Editors’ Choice winner, the Asustor Lockerstor 4 Gen 3 (AS6804T), but you'll need a much larger budget since its $1,299 price tag is more than double that of the DS425+.

Design: Four Lockable Drive Bays

The DS425+ looks very similar to the DS923+ that we reviewed back in 2022. The black enclosure measures 6.5 by 7.8 by 8.7 inches (HWD), weighs 4.9 pounds, and contains four front-loading drive bays. The bays are lockable and use tool-free drive sleds that accommodate 2.5- and 3.5-inch hard drives, which are not included. (At launch, Synology-branded hard drives were required, but the DS425+ now accepts third-party hard drives, with the Synology-branded restriction limited to M.2 drives.)

(Credit: Joseph Maldonado)

Four LED indicators are located to the right of the drive bays to indicate drive activity, as well as one LED to indicate system status. Below the indicators are a power button and a Type-A USB 3.2 (Gen 1) port. Behind two panels at the bottom of the enclosure are a pair of M.2 SSD slots. You can only use Synology-branded M.2 drives in these slots, unless you already have third-party M.2 SSDs in an existing Synology system and want to use them in your new DS425+.

Around back, you’ll find a single 2.5GbE LAN port, a 1GbE LAN port, a secondary USB 3.2 port, a pair of 92mm fans, a power jack, and a reset button. You only get a single 2.5GbE port with this NAS, whereas the Asustor AS6804T is equipped with two 10GbE ports and two 5GbE ports, as well as high-speed USB connectivity with two 40Gbps USB4 Type-C ports.

(Credit: Joseph Maldonado)

The DS425+ uses a 2.0GHz quad-core Intel Celeron J4125 processor and 2GB of DDR4 memory (expandable to 6GB). It supports Synology’s Hybrid RAID, JBOD, Basic, RAID 0, RAID 1, RAID 5, RAID 6, and RAID 10, as well as ext4 and Btrfs file systems. The DS425+ can accommodate up to 80TB of internal storage using four 20TB drives, but it is not compatible with any Synology expansion units.

Software: Intuitive DSM Operating System

As is the case with other Synology network-attached storage devices, the DS425+ uses the intuitive DSM operating system, which offers a Windows-like desktop interface that makes it easy to install and configure the NAS. When you first start the program, the desktop screen is populated with tiles labeled Package Center, Control Panel, File Station, and DSM Help. Use the Package Center to download more than 105 apps for backing up data, using the NAS as a multimedia server or as a surveillance center to manage your security cameras, setting mail and cloud server services, configuring Proxy and VPN servers, and much more.

(Credit: Synology)

The Control Panel tile opens a screen where you can create shared folders, create users and user groups, configure network settings and indexing services, and configure firewall and other security settings. The File Station tile takes you to a screen where you can upload, download, move, and delete files, while the DSM Help tile gives you access to help files and tutorials.

(Credit: Synology)

Tap the Main Menu tile at the top of the screen to access the Storage Manager, where you can organize and monitor storage drives, check drive health, create storage pools, and scrub data. The Main Menu also features a search engine that lets you search for applications and files. Finally, the Resource Monitor displays CPU and memory usage, network traffic, and volume information.

Setup and Performance: The Speed and Ease You Need

Installing the DS425+ is quick and easy. I installed four Synology 4TB Plus Series drives that the company sent along for testing, connected the NAS to a 2.5GbE switch that is connected to my desktop PC, and powered up the NAS. I entered http://find.synology.com in my web browser, and the DS425+ was immediately recognized. I tapped Next and then tapped Install on the next screen to download the DSM operating system. I created a username and password and then created a storage pool and volume.

(Credit: Joseph Maldonado)

Finally, I configured the NAS for SHR (Synology Hybrid RAID) using the Btrfs file system and waited a little more than 6 hours for the drives to be optimized before testing.

The DS425+ performed well in our file transfer tests, which measure read and write times by moving a 4.9GB folder containing a mix of music, video, photo, and office document files between the NAS and a desktop PC.

Its score of 282MBps on the write test and 282MBps on the read test was faster than the QNAP TS-432X-4G, which scored 245MBps on the write test and 272MBps on the read test, but just a hair slower than the Asustor AS6804T, which scored 283MBps on both tests. The Ugreen DXP4800 Plus had a faster write score of 288MBps, but its read score of 168MBps was slower.