Recommended Free Tools
iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
Synology comes to its senses, removes all HDD limitations from 2025 DiskStation models—but only in the broad sense of reversing the major third-party SATA HDD lockout. With DSM 7.3 or later, relevant 2025 DiskStation Plus systems can install third-party HDDs and create storage pools with them, while compatibility-list, support, product-family, and M.2 NVMe restrictions remain.
The change makes 2025 Plus models substantially easier to recommend, but “all HDD limitations” is not a precise description of every storage operation. Synology’s current drive-compatibility policy still distinguishes compatible, unlisted, and incompatible drives, and Synology continues to recommend drives on its compatibility list.
Key takeaways
- DSM 7.3 and later restore third-party HDD installation and storage-pool creation on relevant 2025 DiskStation Plus models.
- The affected consumer range includes the DS225+, DS425+, DS725+, DS925+, DS1525+, and DS1825+, but exact behavior depends on the model and drive type.
- Third-party HDD support does not mean that every unlisted disk is officially compatible or eligible for identical technical support.
- Synology’s current M.2 documentation still requires compatible Synology M.2 NVMe SSDs for M.2 storage pools on supported models.
- DSM 7.3 is the minimum software branch associated with the reversal, although model-specific pages may offer later DSM 7.3.x or newer releases.
What did Synology reverse?
Synology reversed the most controversial part of its 2025 storage-media policy: the restriction on using third-party SATA HDDs in new 2025 DiskStation Plus systems. Under DSM 7.3 or later, affected systems regained the ability to install third-party HDDs and use those disks when creating storage pools.
The reversal followed Synology’s April 2025 announcement that Plus models released from 2025 onward would move toward Synology-branded or certified third-party HDDs for full compatibility and support. Synology said the policy was intended to improve reliability, performance, firmware management, support, and hardware-software integration. The original announcement also said that unlisted HDDs could face restrictions on storage-pool creation and support, while migration from an existing Synology NAS would remain possible without restrictions. Those distinctions matter because the original policy was not simply a rule that every NAS containing a third-party disk would fail to boot. Read the original policy in Synology’s April 2025 announcement and clarification.
#1 Best Overall
- Your Personal Streaming Server - Build your own Netflix-style media library and stream 4K movies, shows and photos to any device without monthly fees
- Create Your Own Cloud - Store your entire photo, video and music collection; access from anywhere with fast 282 MB/s transfer speeds
- Creator-Grade Backup Solution - Protect your irreplaceable content with automated backups to cloud services, external drives and remote NAS
- Multi-Layered Data Protection - Combine RAID redundancy, automated backups and snapshot technology to prevent data loss from any cause
- Smart Home Surveillance - Support up to 30 IP cameras with AI detection, instant alerts and secure remote monitoring
Synology announced DSM 7.3 on October 8, 2025, with expanded storage flexibility among the release’s headline changes. Synology’s current FAQ now describes greater flexibility for third-party HDDs and 2.5-inch SATA SSDs on 2025 DiskStation Plus models. The change is also reflected in independent coverage of the DSM 7.3 policy reversal.
Which 2025 Synology models are affected?
The relevant hardware is primarily Synology’s 2025 DiskStation Plus range, not every Synology NAS launched during 2025. Models prominently associated with the range are listed below.
| Model | Product family | What the DSM 7.3 change means | What to verify |
|---|---|---|---|
| DS225+ | 2025 DiskStation Plus | Third-party HDD use and storage-pool creation are covered by the DSM 7.3-era policy. | Exact drive status, DSM version, and the operation being attempted. |
| DS425+ | 2025 DiskStation Plus | Third-party HDD use and storage-pool creation are covered by the DSM 7.3-era policy. | Exact drive status, DSM version, and the operation being attempted. |
| DS725+ | 2025 DiskStation Plus | Third-party HDD use and storage-pool creation are covered by the DSM 7.3-era policy. | Exact drive status, DSM version, and the operation being attempted. |
| DS925+ | 2025 DiskStation Plus | Third-party HDD use and storage-pool creation are covered by the DSM 7.3-era policy. | Exact drive status, DSM version, and the operation being attempted. |
| DS1525+ | 2025 DiskStation Plus | Third-party HDD use and storage-pool creation are covered by the DSM 7.3-era policy. | Exact drive status, DSM version, and the operation being attempted. |
| DS1825+ | 2025 DiskStation Plus | Third-party HDD use and storage-pool creation are covered by the DSM 7.3-era policy. | Exact drive status, DSM version, and the operation being attempted. |
Synology’s 2025 newsroom listing identifies these products as part of the year’s launches. The compatibility FAQ remains the controlling source for exact series coverage, because Synology applies different policies to different product families and storage types. Do not assume that a 2025 enterprise, rackmount, XS, SA, FS, or surveillance model follows the same rules as a 2025 Plus DiskStation.
What DSM version is required?
DSM 7.3 or later is the software requirement associated with the restored third-party HDD flexibility. A 2025 Plus NAS still running DSM 7.2.2 should not be expected to behave like a system running DSM 7.3.
DSM 7.3 is the minimum relevant branch, not necessarily the newest version available for a particular NAS. Synology’s model-specific Download Center pages may show later DSM 7.3.x maintenance releases or a newer DSM branch. Check the page for the exact NAS model before downloading an update; for example, Synology provides separate pages for the DS225+, DS425+, and DS925+.
Rank #2
- Supports drives on the model's official compatibility list
- Up to 522/565 MB/s sequential read/write throughput supports stable data transfers.
- Dual 2.5GbE ports provide fast network transfer speeds and increased redundancy.
- Leverage built-in file and photo management, data protection, virtualization, and surveillance solutions.
- Backed by Synology's 3-year limited hardware warranty.
DSM can normally be updated through the DSM update interface. Synology also provides model-specific downloads and offline HDD/SSD update packages for systems that cannot connect directly to the internet. Back up important data before a major DSM update, and do not treat a successful update as a substitute for a separate backup.
What does third-party HDD support actually mean?
Third-party HDD support covers several different capabilities, and a disk being detected is not the same as every feature being officially supported.
Windows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallOutdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware match| Operation or capability | Practical interpretation |
|---|---|
| Drive detection | Generally restored on affected 2025 Plus models running DSM 7.3 or later, subject to the exact model and drive status. |
| Fresh installation | DSM 7.2.2-era behavior and DSM 7.3-era behavior can differ. Confirm the current rule before initializing a new system. |
| Storage-pool creation | This is the central HDD capability restored by DSM 7.3. |
| Storage-pool repair or expansion | Do not assume that a disk accepted during initial setup will receive identical treatment during every later operation. Check the exact drive and operation. |
| Drive health information | Health data may be available, but telemetry and monitoring depth can differ between drive models. |
| Firmware updates | Synology-branded drives retain tighter integration with Synology firmware and management workflows. Third-party update behavior can differ. |
| Technical support | Synology recommends compatible or listed drives. Problems attributed to incompatible media may receive more limited support. |
| Hot spares | Do not assume that an unlisted third-party disk can be assigned as a hot spare simply because the disk is visible. |
| Migration | Synology originally stated that migration from an existing Synology NAS would remain possible without restrictions, but migration is not the same as unrestricted future expansion. |
| M.2 NVMe storage pools | These remain subject to a separate Synology-verified SSD requirement on supported models. |
The safe distinction is “works,” “listed as compatible,” and “eligible for full vendor support.” A third-party HDD may work in a DSM 7.3 system without appearing on Synology’s compatibility list. Synology’s FAQ continues to recommend listed drives, which the company says are tested across workloads, abnormal shutdowns, temperature conditions, stress scenarios, and power cycles. Those are Synology’s stated validation criteria and rationale, not independent proof that every listed drive will outperform every unlisted drive. Consult the current Synology drive-compatibility FAQ before buying or replacing a disk.
Does DSM 7.3 remove M.2 SSD restrictions?
No. The HDD reversal does not unlock unrestricted third-party M.2 NVMe storage pools. Synology’s M.2 documentation says that supported models require compatible Synology M.2 NVMe SSDs when creating M.2 storage pools.
The 25-series models listed by Synology for M.2 storage pools include the DS1825+, DS1525+, DS925+, DS725+, and DS425+. The DS225+ is not included in that listed group. Synology also states that DSM cannot be installed solely on an M.2 SSD; at least one non-M.2 drive is required for DSM installation. See Synology’s M.2 storage-pool requirements before purchasing an NVMe drive.
Rank #3
- Secure private cloud - Enjoy 100% data ownership and multi-platform access from anywhere
- Easy sharing and syncing - Safely access and share files and media from anywhere, and keep clients, colleagues and collaborators on the same page
- Automated Backup Protection - Set-and-forget backups for Macs, PCs and mobile devices to multiple destinations including cloud and external drives
- Home Security System - Record and monitor your property 24/7 with support for multiple IP cameras and remote viewing
- 2-Year Warranty - Reliable hardware backed by Synology's expert customer support team and ongoing software updates
| Storage type | DSM 7.3-era position | Buyer implication |
|---|---|---|
| Third-party SATA HDD | Use and storage-pool creation restored on relevant 2025 Plus models. | Check the exact model, drive status, and support implications. |
| Third-party 2.5-inch SATA SSD | Greater flexibility described in Synology’s current FAQ, subject to the stated policy. | Do not confuse SATA SSD support with M.2 NVMe pool support. |
| Synology M.2 NVMe SSD | Required for M.2 storage pools on supported models. | Budget for Synology-compatible M.2 media if an M.2 pool is part of the plan. |
| Third-party M.2 NVMe SSD | Not generally unlocked for M.2 storage-pool creation by the HDD reversal. | Do not buy a consumer NVMe drive assuming DSM 7.3 will accept it for a storage pool. |
Can existing owners use third-party disks safely?
Existing owners should first identify the exact NAS model, confirm the installed DSM version, back up important data, and verify the disk in Storage Manager before creating or expanding a storage pool.
- Identify the model. Confirm whether the NAS is one of the relevant 2025 DiskStation Plus models rather than assuming that every 2025 Synology product qualifies.
- Check DSM. Open DSM’s update controls or the model-specific Synology Download Center page and confirm that the system is running DSM 7.3 or later.
- Back up the data. Preserve a Hyper Backup or equivalent backup and a separate recovery path before changing DSM, RAID, SHR, or drive assignments.
- Check the exact disk. Compare the full drive model number and firmware status with Synology’s compatibility list. A brand name such as Seagate, Western Digital, or Toshiba is not enough to establish compatibility.
- Confirm the operation. Installing a disk, creating a new pool, repairing a pool, expanding a pool, assigning a hot spare, and migrating an existing pool are different operations.
- Review the result. Confirm the disk’s status in Storage Manager, then verify the RAID or SHR layout, usable capacity, health monitoring, and backup coverage before placing important data on the pool.
Drive mixing also deserves caution. Capacity, sector format, performance, firmware behavior, noise, vibration, power consumption, and physical clearance can affect a RAID or SHR array even when DSM accepts the disks. Large-capacity enterprise drives should be checked particularly carefully for SATA behavior, sector format, power draw, vibration, and bay clearance.
Can owners migrate disks from an older Synology NAS?
Synology stated in its original announcement that migration from an existing Synology NAS to a new 2025 Plus model would remain possible without restrictions. Migration does not automatically mean that every future replacement, expansion, or hot-spare operation will receive identical treatment.
Before migration, verify the supported route for the exact source and destination models, create a Hyper Backup or equivalent backup, record the existing drive order and RAID/SHR configuration, and avoid destructive initialization if preserving the existing volume is the goal. Check DSM and package compatibility after the move. Migration is a convenience, not a backup strategy.
Is a 2025 Synology DiskStation safe to buy now?
A 2025 Synology Plus DiskStation is much safer to recommend than it was under the original April 2025 policy, provided the buyer accepts Synology’s remaining compatibility and M.2 rules. DSM 7.3 restored the core HDD flexibility that many NAS buyers expect, but the reversal does not erase the uncertainty created by Synology’s earlier policy or guarantee that future DSM releases will preserve the current position.
The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Rank #4
- Celeron J4125 4-Core 2.0GHz CPU, Up To 2.7GHz Turbo; 6GB DDR4 non-ECC SODIMM Memory; 8TB (2 x 4TB) 6Gb/s SATA HDDs for High-Capacity Storage
- Consolidate and Safeguard: Integrated security features ensure centralized access and protect all your data, offering a secure and streamlined storage solution.
- Comprehensive Data Management: Manage and share various types of data, including files, photos, and surveillance videos, enabling easier access, backup, and sharing.
- Energy Efficiency: With an operational power usage as low as 15 watts, the DS224+ minimizes energy impact, reducing operating costs while efficiently managing your data.
- Enhanced Performance: The DS224+ excels in indexing files within Synology Drive and Synology Photos and handles demanding web applications better than its predecessors, providing faster response times and indexing speeds.
| Buyer priority | Synology 2025 Plus fit | What to consider |
|---|---|---|
| Familiar DSM applications and administration | Strong fit | DSM, integrated backup, file synchronization, surveillance, and account-management tools remain central advantages. |
| Third-party SATA HDD choice | Much better fit under DSM 7.3 or later | Verify the exact drive and accept that listed drives remain Synology’s preferred support path. |
| Third-party M.2 NVMe storage pool | Poor fit | Synology’s current documentation requires compatible Synology M.2 SSDs for supported M.2 pools. |
| Maximum component freedom | Potentially poor fit | Consider QNAP, UGREEN, ASUSTOR, TerraMaster, or a DIY system. |
| Long-term policy certainty | Requires caution | The reversal is current policy, not a contractual guarantee that storage rules cannot change again. |
Buyers should choose based on bay count, networking, CPU, memory, expansion, software requirements, and the complete cost of the enclosure plus drives—not merely on whether DSM accepts a particular HDD. Synology’s product-status database lists the DS225+, DS425+, DS725+, DS925+, and DS1525+ as generally available with full DSM update and technical-support status at the time of the supplied research.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Should you choose Synology or a more open NAS platform?
Synology remains attractive for buyers who value polished appliance-like administration, integrated backup and synchronization tools, surveillance, and a familiar DSM environment. Synology’s compatibility list and vendor-validation process can also appeal to businesses that prefer a defined support path over maximum component choice.
QNAP, UGREEN, ASUSTOR, TerraMaster, and DIY systems are relevant alternatives for buyers who consider unrestricted hardware selection more important than Synology’s integrated ecosystem. Each platform requires model-specific evaluation rather than a blanket recommendation.
| Platform | Why consider it | Trade-off to investigate |
|---|---|---|
| QNAP | Broad product range, extensive hardware options, and generally open component selection. | Software complexity, security practices, support model, and the exact product line. |
| UGREEN NAS | Consumer-focused hardware and attractive specifications. | Newer NAS software and a shorter platform track record than Synology. |
| ASUSTOR | Competitive hardware and broad third-party-drive approach. | Smaller first-party application ecosystem than Synology. |
| TerraMaster | Competitive hardware pricing and drive flexibility. | Software polish and ecosystem depth vary by model. |
| DIY TrueNAS or Unraid | Maximum control over hardware, disks, operating system, and upgrades. | The owner assumes responsibility for assembly, maintenance, backups, compatibility, and support. |
Compare QNAP, UGREEN, ASUSTOR, TerraMaster, TrueNAS, and Unraid using the same criteria: third-party-drive freedom, backup and sync software, containers and virtual machines, surveillance licensing, expansion, warranty, noise, power consumption, networking, migration, and long-term vendor lock-in.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
What should you check before buying?
- Confirm the exact 2025 DiskStation model and whether the model is covered by the current drive-compatibility policy.
- Plan around DSM 7.3 or later, then check the model-specific Download Center for the newest supported branch and maintenance release.
- Search the compatibility database by exact HDD or SSD model number rather than by manufacturer name.
- Decide whether the system needs SATA SSD storage, an M.2 storage pool, cache, or only conventional HDD storage.
- If an M.2 storage pool matters, budget for Synology-compatible M.2 NVMe SSDs.
- Price the enclosure, complete drive set, optional SSDs, expansion units, and support plans together.
- Confirm whether an unlisted disk is acceptable for the intended business or home workload and support expectations.
- Maintain an independent backup before migration, pool creation, expansion, repair, or replacement.
- Do not assume that today’s DSM 7.3 policy guarantees identical rules in future DSM releases.
Synology does not publish dependable current U.S. street prices in the supplied research. At publication, compare the enclosure-only price and the complete populated-system price by geography, seller, drive capacity, warranty, and included accessories. Synology’s where-to-buy page is the appropriate starting point for current availability.
Best Value
- Complete Phone & Computer Backup - Automatically protect photos, documents and videos from iPhone android, Mac and Windows to one secure location
- Your Private File Cloud - Access files from anywhere and share large projects with family or clients without relying on expensive cloud subscriptions
- Smart Home Security Hub - Monitor your home 24/7 with AI-powered surveillance that detects people, vehicles and sends instant alerts
- 100% Data Ownership - Keep full control of your personal data with multi-platform access and no monthly subscription fees
- 2-Year Warranty - Reliable hardware backed by Synology's expert customer support team and ongoing software updates
Frequently Asked Questions
Does DSM 7.3 support third-party HDDs on the DS225+ and other 2025 Plus models?
Yes. On relevant 2025 DiskStation Plus models, DSM 7.3 or later restores third-party HDD installation and storage-pool creation, subject to the exact drive’s status and Synology’s current policy. A detected drive is not automatically a listed or fully supported drive.
Does DSM 7.3 remove third-party M.2 NVMe restrictions?
No. Synology’s current documentation still requires compatible Synology M.2 NVMe SSDs for M.2 storage pools on supported models. DSM also cannot be installed solely on an M.2 SSD.
Can I migrate disks from an older Synology NAS to a 2025 Plus model?
Synology stated that migration from an existing Synology NAS would remain possible without restrictions. Owners should still verify the exact migration path, back up data, record the RAID or SHR layout, and distinguish migration from future expansion or drive replacement.
Free tools Windows power users keep installed
One-click scans. No signup required.
Are all third-party NAS HDDs officially supported now?
No. DSM 7.3 restores important third-party HDD functionality, but Synology continues to distinguish compatible, unlisted, and incompatible drives and recommends drives on its compatibility list. Check the exact model number rather than relying on the Seagate, Western Digital, or Toshiba brand name.
The Bottom Line
DSM 7.3 makes 2025 Synology Plus DiskStations substantially easier to recommend because the major third-party SATA HDD restriction has been reversed. The accurate verdict is not that every storage limitation disappeared: Synology still controls its compatibility-list and support path, and M.2 NVMe storage pools remain tied to compatible Synology SSDs. Buy a 2025 Plus model if DSM and Synology’s ecosystem matter to you; choose a more open platform if maximum hardware freedom and policy certainty matter more.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
