Synology removed its third-party hard drive block in DSM 7.3, so drive choice is no longer the main reason to look for the best Synology alternative. The reasons that remain are hardware and software: a DS925+ at about $770 still ships 4 GB of RAM, two 2.5GbE ports and a Ryzen V1500B with no integrated GPU, and an unlisted M.2 NVMe drive still cannot form a storage pool on any 2025 Synology model.
This guide covers the four appliance brands that replace a DiskStation (UGREEN, QNAP, TerraMaster and UniFi UNAS) plus a DIY TrueNAS or Unraid build. It maps each major DSM app to its equivalent on every platform, and it closes with a copy plan that moves a full Synology volume without the proprietary Hyper Backup archive format.
Compared October 2026 against DSM 7.4.1.
Best Synology alternatives: quick picks
| Award | Pick | Price (check live) | Why it wins |
|---|---|---|---|
| Best overall | UGREEN DXP4800 Plus | about $657 | Replaces a DS925+ for about $110 less, with 8 GB DDR5, 10GbE and Quick Sync |
| Best value | QNAP TS-464-8G | about $509 | Closest app set to DSM, including free bare-metal PC backup and an 8-channel NVR |
| Best 2-bay | UGREEN DXP2800 | about $390 | 8 GB RAM and two M.2 slots that can hold a storage pool, against 2 GB and no M.2 on the DS225+ |
| Best SHR replacement | TerraMaster F4-425 Pro | about $700 (about $595 direct) | TRAID mixes drive sizes the way SHR does; 8-core N305 and two 5GbE ports |
| Best backup target | UniFi UNAS Pro 4 | about $549 at store.ui.com, surcharge included | Two 10G SFP+ ports, Time Machine and rsync pull from a DiskStation, for less than a DS425+ |
| Best DIY | Jonsbo N3 case | about $150 (case only) | Eight 3.5-inch bays for TrueNAS or Unraid, with no vendor OS between you and the disks |
What still pushes owners off Synology in 2026
The October 2025 reversal is narrower than most coverage suggests. The Synology drive compatibility policy page splits the rules by product line, and the M.2 rule did not change for any of them. The policy covers models launched from 2025 onward; older units such as the DS923+ were never affected.
| 2025+ model line, DSM 7.3 and later | Unlisted HDD | Unlisted 2.5-inch SATA SSD | Unlisted M.2 NVMe |
|---|---|---|---|
| DS Plus and desktop FS (DS225+, DS425+, DS925+, DS1825+) | New pool allowed | New pool and cache allowed | Migration only, no new pool or cache |
| Value and J series | New pool allowed | Allowed | Not applicable (no M.2 row) |
| RS Plus rackmounts | Migration only | Allowed, marked unverified | Migration only |
| XS, XS+, rackmount FS, SA, HD, UC | Migration only | Migration only | Migration only |
Five problems remain after the reversal, and each one is measurable:
- NVMe pricing. The Synology SNV5420-400G lists at about $587 on Amazon against about $237 for a 1 TB Samsung 990 EVO Plus. That is 2.5x the price for 40% of the capacity, or $1.47 per GB against $0.24.
- A new feature lock. DSM 7.4 requires Synology hard drives for post-processing deduplication and compression, and the three Synology HAT3310 12 TB and 16 TB Amazon listings checked for this guide are out of stock.
- Media processing moved off the box. DSM 7.2.2 removed Video Station and handed HEVC, H.264 and VC-1 processing to client devices, and DSM 7.3 kept that change. The 2025 J4125 models also ship without the Intel i915 driver, so Plex hardware transcoding needs a community workaround over SSH, while the R1600 and V1500B models have no GPU at all.
- RAM. The DS225+ and DS425+ ship 2 GB onboard plus one empty slot, 6 GB maximum; UGREEN and QNAP ship 8 GB in the same price band.
- End of updates. DSM 7.4 is the last major version for the DS918+, DS218+, DS718+, DS1019+, DS1618+, DS1819+ and DS2419+, which puts a deadline on most 2016 to 2019 Plus, Value and J models still in service.
None of this makes DSM a bad operating system. Active Backup for Business, Synology Photos and Hyper Backup remain the most complete bundle on any appliance, and the app map further down shows where every alternative falls short of them.
How the picks were chosen
Every number in this guide comes from a manufacturer spec page or datasheet, cross-checked against a live retailer listing and one independent review. Amazon prices, sellers and stock were read through the Amazon Creators API on October 5, 2026, and each pick is sold by the manufacturer or by Amazon itself. Idle power figures come from the cited reviews, because UGREEN lists an identical 42.36 W figure for four different models (three 4-bay, one 2-bay). None of these units was benchmarked on the test bench for this guide; the measured transcode and drive numbers live in the linked articles.
Excluded: the ARM-based UGREEN DH2300 (no Docker) and DH4300 Plus (no virtual machines), the QNAP TS-462A (costs more than the TS-464 with one 2.5GbE port and no PCIe slot), the TerraMaster N95 variants (the manufacturer spec text contradicts itself on RAM type and clock), the Asustor AS5404T (only available from a third-party seller), and the TrueNAS Mini X+ (sold direct for $2,160 diskless, more than three times the price of a DXP4800 Plus).
Synology alternatives compared
The two Synology rows are the baseline. Hardware transcoding means an iGPU that Plex or Jellyfin can use without a workaround.
| Model | Price | CPU and HW transcode | RAM shipped / max | Bays + M.2 pool | Network | Warranty |
|---|---|---|---|---|---|---|
| Synology DS925+ | about $770 | Ryzen V1500B, no iGPU | 4 GB ECC / 32 GB | 4 + 2 (Synology NVMe only) | 2x 2.5GbE | 3 years |
| Synology DS425+ | about $598 | Celeron J4125, i915 removed | 2 GB / 6 GB | 4 + 2 (Synology NVMe only) | 1GbE + 2.5GbE | 3 years |
| UGREEN DXP4800 Plus | about $657 | Pentium Gold 8505, Quick Sync | 8 GB DDR5 / 64 GB | 4 + 2 Gen4, any brand | 10GbE + 2.5GbE | 2 years |
| QNAP TS-464-8G | about $509 | Celeron N5095, Quick Sync | 8 GB DDR4 / 16 GB | 4 + 2 Gen3 x1 | 2x 2.5GbE, PCIe Gen3 x2 slot | 3 years |
| UGREEN DXP2800 | about $390 | N100, Quick Sync | 8 GB DDR5 / 16 GB | 2 + 2 | 1x 2.5GbE | 2 years |
| TerraMaster F4-425 Pro | about $700 | Core i3-N305, Quick Sync | 8 GB DDR5 / 32 GB | 4 + 3 Gen3 x1 | 2x 5GbE | 2 years |
| UniFi UNAS Pro 4 | about $549 | 4x Cortex-A57 ARM, none | 8 GB, not upgradeable | 4 + 2 (cache only) | 2x 10G SFP+ + 1GbE | 2 years direct |
| DIY: Jonsbo N3 | about $150 + board | Your choice | Your choice | 8 + board M.2 | Board dependent | Per part |
1. UGREEN DXP4800 Plus: best overall Synology replacement
The DXP4800 Plus is the direct answer to a DS925+: four bays, two M.2 slots and a newer Intel CPU, for about $110 less on Amazon at the time of writing. It suits a DS920+ or DS918+ owner who runs Docker containers, Plex or Jellyfin, and a few shares, and who wants 10GbE without an add-in card.
- CPU: Pentium Gold 8505, 5 cores and 6 threads, with UHD Graphics (48 EU) and Quick Sync for hardware transcoding.
- Memory: 8 GB DDR5 in two SODIMM slots, 64 GB maximum. The UGREEN “ODECC” label refers to the on-die error correction built into DDR5, not system ECC.
- Storage: four SATA bays, two PCIe 4.0 M.2 slots that accept any brand as cache or as a separate pool, and a 128 GB boot SSD that keeps UGOS Pro off the data drives.
- Network: one 10GbE port and one 2.5GbE port. KitGuru measured 24.25 W idle on 2.5GbE and 30.45 W on 10GbE with four WD Red drives installed.
- Warranty: 2 years, one year shorter than the Synology term of 3.
The catch: it is the wrong box for anyone who depends on Active Backup for Business or Surveillance Station. UGREEN documents file-level PC backup but no bare-metal image backup, and the UGOS Pro feature list names no NVR app. Pool portability is the second catch: an investigation by a UGREEN customer found that UGOS Btrfs and ext4 pools set on-disk feature flags that stock Linux refuses to mount, while Synology documents how to read an SHR volume on Ubuntu. The BIOS is open, so TrueNAS or Unraid can replace UGOS Pro on the same hardware, and the TrueNAS and Unraid guide for the UGREEN Ultra models covers the BIOS steps on the same family.
2. QNAP TS-464-8G: best value and the closest app set to DSM
QTS is the only alternative OS that matches DSM app for app. HDP PC Agent does free full-system and bare-metal PC backup, HDP for PC/VM backs up VMware and Hyper-V without licences, HBS 3 replaces Hyper Backup, Qsync replaces Synology Drive, and QVR Pro includes 8 camera channels free (playing back recordings older than 14 days in QVR Pro Client needs the paid Unlimited Playback licence). At about $509 sold by Amazon.com, it is also about $90 cheaper than a DS425+ and ships four times its RAM.
- CPU: Celeron N5095, 4 cores, with UHD Graphics for hardware transcoding.
- Memory: 8 GB DDR4 in two slots, 16 GB maximum. QuTS hero (ZFS) needs 8 GB, so the 8G model can run it.
- Storage: four bays and two M.2 2280 slots at PCIe Gen3 x1, usable as cache or storage.
- Expansion: a PCIe Gen3 x2 slot, the only one among the 4-bay picks here, which takes a 10GbE card or an M.2 adapter.
- Network and power: two 2.5GbE ports; QNAP rates it at 21.6 W with disks in standby and 40.5 W in operation. Warranty is 3 years.
Where it falls short: headroom. The N5095 platform dates from 2021, the RAM ceiling is 16 GB, and each M.2 slot runs at about 1 GB/s. The QNAP security record also needs to be part of the decision: Qlocker in April 2021 and DeadBolt in January 2022 hit internet-exposed QTS boxes, and the TS-453E was compromised several times at Pwn2Own Ireland 2025 (the DS925+ was rooted twice at the same event). Keep QTS off the public internet, reach it through a VPN, and apply QSA advisories as they ship.
3. UGREEN DXP2800: best 2-bay replacement for a DS225+
The DS225+ costs about $365 and ships 2 GB of RAM with no M.2 slot. The DXP2800 costs about $25 more and ships 8 GB DDR5 plus two M.2 slots that can hold an SSD pool for Docker volumes and app data. It fits a 2-bay home server: photo backup, a Jellyfin library and a handful of containers.
- CPU: Intel N100, 4 cores, with Quick Sync. Ocinside measured about 7 W idle and 34.7 W at maximum load.
- Memory: 8 GB DDR5, 16 GB maximum.
- Storage: two bays, two M.2 slots (cache or pool), and a 32 GB eMMC boot device rather than a boot SSD.
- Network: a single 2.5GbE port. Warranty is 2 years.
Look elsewhere if the NAS feeds a 10GbE desktop. The DXP2800 GT adds a 10GbE port for about $460, but it swaps the N100 for an AMD Ryzen R2514, which has no Quick Sync and no AV1 decode, so Plex transcoding is weaker on it. The same trade applies one size up, where the DXP4800 GT gives two 10GbE ports for about $560.
4. TerraMaster F4-425 Pro: best SHR replacement for mixed drive sizes
SHR is the feature Synology owners miss first. It lets a pool grow one larger drive at a time while still using the full capacity of mixed sizes. Among the appliance brands here, only TRAID in TerraMaster TOS 7 offers the same model; UGOS Pro, QTS and UniFi Drive all use fixed RAID levels. The F4-425 Pro pairs TRAID with the strongest CPU in this price class.
- CPU: Core i3-N305, 8 cores, with UHD Graphics (32 EU) and Quick Sync.
- Memory: 8 GB DDR5 in a single slot. TerraMaster lists 32 GB, while Intel ARK lists 16 GB as the official maximum for the N305.
- Storage: four bays and three M.2 2280 slots at PCIe 3.0 x1, which can form their own RAID 5 SSD pool.
- Network: two 5GbE ports, which reach roughly half of 10GbE throughput without SFP+ cabling.
- Power: TerraMaster rates it at 45 W under read and write load and 14 W in hibernation. Warranty is 2 years.
Buy it direct, not on Amazon. The same N305 model costs about $595 on the TerraMaster store against about $700 on Amazon, a gap of about $105. There is also no PCIe slot, so 5GbE is the ceiling for the life of the box.
5. UniFi UNAS Pro 4: best Hyper Backup and Time Machine target
UNAS is a file and backup appliance, and that is the right way to judge it. UniFi Drive serves SMB and NFS, acts as a Time Machine target, backs up to another UNAS, an SMB server, Backblaze B2, S3 or Wasabi, and since version 4.2.2 it can pull data from a remote rsync server, which includes a DiskStation. It suits a UniFi network with a rack, where the Synology keeps running apps and the UNAS takes the backups, or where the apps move to a mini PC.
- CPU and memory: quad Cortex-A57 at 2.0 GHz with 8 GB RAM, neither upgradeable nor ECC.
- Storage: four bays with RAID 5, 6 or 10, and two M.2 slots that work as cache only.
- Network: two 10G SFP+ ports plus one 1GbE port, in a 1U chassis.
- Price: about $549 at store.ui.com with the surcharge included ($499 before it), with a 2-year warranty when bought direct.
Not for app hosting. UniFi Drive has no Docker, no virtual machines, no app store, no Plex and no desktop sync client. Amazon listings for every UNAS model come from third-party resellers at roughly 13% to 89% over the surcharge-included store price. An authorised reseller purchase carries a 1-year warranty instead of 2, and Ubiquiti gives none at all on units from unauthorised sellers, so buy direct. For a desktop backup box, the UNAS 2 costs about $219 but supports RAID 1 only.
6. DIY TrueNAS or Unraid in a Jonsbo N3: best for control
A DIY build removes the vendor OS from the decision. TrueNAS Community Edition is free and replaces Snapshot Replication with native ZFS snapshots and replication, while the Unraid array is the closest DIY equivalent to SHR: drives of any size, with parity at least as large as the largest data drive. Unraid licences cost $49 (Starter, 6 devices), $109 (Unleashed) or $249 (Lifetime). The TrueNAS vs Unraid comparison covers which one fits which workload.
- Case: the Jonsbo N3 holds eight 3.5-inch drives and one 2.5-inch drive, takes mini-ITX boards and SFX power supplies up to 105 mm, and fits a 130 mm CPU cooler.
- Board: Intel N150 six-SATA ITX boards are the common pairing, but their six SATA ports share an ASM1166 controller on one PCIe 3.0 lane, and NASCompares measured about 650 MB/s across six drives on a CWWK board with that layout. That is enough for hard drives behind 2.5GbE and too slow for an SSD array.
- Memory: N150 boards advertise up to 48 GB on one SODIMM, while Intel lists 16 GB as the supported maximum.
Support is the cost. A DIY box has a warranty per part and no vendor to call, and the build itself takes an afternoon. The DIY NAS vs prebuilt cost comparison prices the full build against a DS425+, and the NAS case guide lists alternatives to the N3.
DSM app replacement map
“Docker” means a self-hosted container you deploy and update yourself; “none” means no native or catalogued equivalent was found. The rows are ordered by how often each DSM app is the reason an owner stays.
| DSM app | UGOS Pro (UGREEN) | QTS / QuTS hero (QNAP) | UniFi Drive (UNAS) | TrueNAS / Unraid |
|---|---|---|---|---|
| Active Backup for Business (PCs) | File-level PC backup; no bare-metal image documented | HDP PC Agent, free, bare-metal restore | none | Docker: UrBackup |
| Active Backup (VMs) | none | HDP for PC/VM, VMware and Hyper-V | none | none native |
| Active Backup for Microsoft 365 | none | HDP for SaaS, free for 30 users | OneDrive backup, work and school accounts only | none native |
| Synology Photos | Photos | QuMagie | iPhone backup through UniFi Endpoint, no library | Immich |
| Synology Drive | Desktop client with sync | Qsync | File access only, no sync client | Docker: Nextcloud or Syncthing |
| Hyper Backup | Sync & Backup (rsync based) | HBS 3 | Backup to UNAS, SMB, B2, S3, Wasabi | Cloud Sync tasks, rsync, ZFS replication |
| Snapshot Replication | Snapshots on Btrfs pools | Snapshots; immutable on QuTS hero h6.0 | Snapshots | ZFS snapshots and replication |
| Surveillance Station | none listed | QVR Pro, 8 channels free; playback past 14 days paid | none (UniFi Protect runs on a separate NVR) | Docker: Frigate |
| Container Manager | Docker | Container Station | none | Native apps (Docker) |
| Virtual Machine Manager | Virtual Machine | Virtualization Station | none | Native VMs |
| QuickConnect | UGREENlink | myQNAPcloud | UniFi Site Manager | Tailscale app |
| SHR | none, fixed RAID levels | none, fixed RAID levels | none, fixed RAID levels | Unraid array (mixed sizes); TrueNAS RAIDZ expansion adds disks but not mixed sizes |
| Time Machine | Yes | Yes | Yes | Yes |
Two rows decide most migrations. An office that images Windows PCs with Active Backup has one appliance replacement: HDP on QNAP. A household that relies on SHR to grow storage one drive at a time has TRAID on TerraMaster or a DIY Unraid build, and nothing else on this list.
Moving the data off a DiskStation
No vendor ships a one-click Synology importer. UGREEN, QNAP and UniFi all document the same path: run rsync between the two boxes and recreate users, shares and apps by hand. The UGREEN migration guide states the limit directly: users, applications, snapshots and platform metadata do not migrate, and that includes photo albums and face tags.
Step 1: Copy with rsync, not a Hyper Backup archive
A Hyper Backup task writes .hbk archives that only Hyper Backup, Hyper Backup Explorer or Hyper Backup Vault can read. For a migration, either enable the rsync service in DSM under Control Panel > File Services > rsync and pull from the new box (UGOS Pro and UniFi Drive 4.2.2 or newer both support a pull), or, for a QNAP target, run the HBS 3 rsync server and create a Hyper Backup task with the “rsync copy (single-version)” destination, which writes plain files.
Step 2: Keep the old disks readable
Leave the Synology disks untouched until the copy is verified. If the DiskStation fails mid-migration, the Synology PC recovery procedure reads an SHR or classic RAID volume on Ubuntu: install mdadm and lvm2, assemble with mdadm -AsfR, activate with vgchange -ay, and mount the volume read-only. It does not apply to volumes with a read-write SSD cache, so remove that cache on the DiskStation before the move.
Step 3: Do not move the disks into the new NAS
SHR disks cannot be imported into UGOS Pro, QTS, TOS or UniFi Drive. The new box initialises its own pool, which wipes the drives, so the migration needs enough new capacity to hold a full copy. With a WD Red Plus 12 TB at about $460 on Amazon at the time of writing, four of them cost about $1,842, more than any 4-bay box in this guide; the NAS hard drive guide tracks current CMR prices by capacity.
Copy time for a full DiskStation, by link speed
| Data to copy | 1GbE (110 MB/s) | 2.5GbE (280 MB/s) | 10GbE, source array at 500 MB/s |
|---|---|---|---|
| 8 TB | 20.2 h | 7.9 h | 4.4 h |
| 16 TB | 40.4 h | 15.9 h | 8.9 h |
| 32 TB | 80.8 h | 31.7 h | 17.8 h |
The table assumes sustained large-file throughput: 110 MB/s is the practical ceiling of 1GbE, 280 MB/s of 2.5GbE, and 500 MB/s is an assumed sequential rate for a four-drive hard disk array rather than a 10GbE limit. A photo library with millions of small files runs well below these figures, and rsync over SSH can be CPU-bound on a J4125 below the 2.5GbE figure. The column that matters is set by the slower box: a DS925+ or DS425+ has no 10GbE option, so a copy from either one tops out at the 2.5GbE column whatever the destination supports. For a broader look at which NAS to land on, see the NAS picks for Plex and self-hosting and, for the cheaper Synology line, the neo+ vs Plus comparison.
