Synology Third-Party Drives

For an HDD order, start with the WD Red Plus WD80EFPX, then check your exact NAS and installed DSM release before buying. Synology's DSM 7.3-and-above policy allows unlisted third-party HDDs and 2.5-inch SATA SSDs in the covered 2025 DiskStation Plus models, but unlisted M.2 NVMe drives remain restricted for new pools and cache. For an SSD order, use the conditional DS925+/SNV5420-800G example below rather than a universal Synology SSD pick.

Official policy, specifications and compatibility entries checked November 2, 2026. This guide is based on published documentation.

Quick picks: match the job before the drive

The enclosure rows identify the lookup to use; keep your existing NAS if it meets your needs. Sources: WD specifications, DS225+, DS425+, DS925+, and the SSD specifications plus entry note.

Copy the exact enclosure, DSM release and drive identity

Open Control Panel → Info Center → General: Synology's Info Center help identifies this as the place to find the model name and DSM version. Copy the complete version, including build and update suffix. For an unopened NAS, treat the installed release as unknown until confirmed; do not assume the policy threshold is already installed.

DSM 7.3 is a policy threshold, not the latest DSM claim. The DS925+ release feed checked November 2 lists 7.4.1-90080 Update 1, published October 12, 2026. Your installed release and an individual drive entry's minimum release still control the order.

Use this inventory before opening a shop:

1. 1

   Enclosure and software

   Copy the exact NAS name and complete installed DSM version.

2. 2

   Drive and quantity

   Copy the manufacturer's part number, capacity, firmware if known, and number of drives.

3. 3

   Role and operation

   Choose SATA storage, NVMe cache or NVMe storage pool; identify a fresh setup, replacement or migration.

Read the policy for that model and operation

Choose the SSD's job first. A SATA SSD occupies a main drive bay; NVMe cache mounts on an existing volume to improve random access, while an M.2 storage pool supplies separate storage. Synology's drive-replacement rules prohibit mixing HDDs and SSDs in the same pool: buying an SSD does not make it an eligible replacement for an HDD in that pool.

Synology's drive-policy FAQ, updated May 27, 2026 and checked November 2, separates series, drive types and operations. For its DS Plus, DSM 7.3-and-above scope:

These are policy permissions, not a promise that every drive fits or receives full support. For unlisted drives, the compatibility list's support notice limits assistance to system hardware, software and configuration, excluding issues caused by the drive or its firmware.

Do not transfer this table to RackStation Plus or enterprise systems: the FAQ gives them different rows. It also explicitly says the new policies do not apply retroactively to models launched before 2025. For an older NAS or an older installed release, resolve its applicable documentation before ordering.

Find and save the official compatibility result

Open Synology's compatibility list. Under Select your system, choose your exact enclosure and drive location, then Find drives. Check the SATA HDD/SSD results for bay drives and Built-In M.2 Slot for NVMe; an adapter or expansion-unit category is a different lookup.

Search the full part number, not just “Red Plus” or “Synology SSD.” Match capacity and firmware, open View/Notes, and check incompatible models and the change log when offered. Check every result page, clear filters, and inspect both Synology and third-party views if shown before declaring a drive absent. Synology cautions that firmware or hardware changes can affect compatibility.

Save the result URL and a dated PDF or screenshot showing the selected NAS/category, matching row, firmware, capacity and notes. If no row matches, save that result and the incompatible lookup too; an empty compatible search alone does not establish a supported order. Keep the installed DSM version alongside the saved policy link.

• Yes: Buy candidate: exact listed entry, notes and intended role all match
• Partly: Conditional: unlisted SATA drive permitted by the applicable policy; support limits accepted
• No: Pause: incompatible entry, unknown DSM, unresolved firmware note or unlisted NVMe for a new pool/cache

Starting HDD candidate: WD Red Plus 8 TB WD80EFPX

WD's exact-model specifications identify WD80EFPX as an 8 TB CMR 3.5-inch SATA drive. It is a useful starting candidate for SATA storage, conditional on the compatibility check. “8 TB WD Red” alone is insufficient: copy the entire model number and recheck any substituted capacity or suffix.

Worked HDD order: consider WD80EFPX for a DS925+ running DSM 7.3. Our saved November 2 compatible SATA response does not list WD80EFPX; the incompatible response contains no rows. Classify this as unlisted, then apply the DS Plus HDD policy and decide whether its limited support is acceptable. If you require a listed drive, pause and select a matching listed alternative; do not label WD80EFPX “Synology verified.”

after completing the check. Return to best NAS hard drives to compare drive choices once compatibility is resolved.

Two-bay SATA reference: Synology DS225+

The DS225+ specifications list two bays for 3.5-inch SATA HDDs or 2.5-inch SATA SSDs. It has no M.2 slots, so exclude the NVMe candidate from a DS225+ order. A SATA SSD still needs its own model/capacity lookup and intended-role check; do not borrow an HDD's compatibility result.

Four-bay reference with M.2 options: Synology DS425+

The DS425+ specifications list four SATA bays and two M.2 2280 NVMe slots. Synology's M.2 pool guidance includes DS425+, but requires compatible Synology M.2 SSDs. Choose cache or a pool before looking up the SSD; slot presence alone does not establish either order's eligibility.

Worked-order enclosure: Synology DS925+

The DS925+ also has four SATA bays and two M.2 2280 NVMe slots and appears in the M.2 pool guidance. Its shared product page includes DS925neo+: the memory table distinguishes 4 GB ECC on DS925+ from 4 GB non-ECC on DS925neo+. Copy the actual suffix instead of treating the two names as interchangeable, and select that exact enclosure in the compatibility tool.

For a new enclosure decision, use best NAS for home; for the platform trade-offs, see Synology vs UGREEN.

Conditional SSD candidate: Synology SNV5420-800G

The SNV specifications identify this version as 800 GB, M.2 2280, NVMe PCIe 3.0 x4. The same table includes SNV5420-400G and SNV5420-1600G, with different capacities and endurance specifications; do not transfer a row between them.

Worked SSD order: the DS925+ M.2 response includes SNV5420-800G / FG2N904 / 800GB. Its View note requires DSM 7.4.1-90080 or newer before installing. A DS925+ still running DSM 7.3 must pause that order until the documented requirement is met; the general policy threshold does not override this note.

For cache, establish the workload first. Synology's cache guidance targets frequently accessed random small blocks and expects minimal gains for large-file sequential access or video playback. Its creation guide requires at least one SSD for read-only cache and at least two for read-write cache; check memory requirements before choosing capacity.

For a storage pool, verify the enclosure in the M.2 pool guidance and the exact SSD entry. DSM cannot be installed on M.2 SSDs: Synology requires at least one non-M.2 drive for DSM installation. Plan the SATA drive too. The SSD's Amazon identity awaits owner verification; use the maker link above.

Installation, migration and independent backup

Follow the enclosure manual for installation. Synology's M.2 guidance requires a complete shutdown and disconnection of power and cables before inserting or removing M.2 SSDs; they are not hot-pluggable. Its drive-status guidance recommends updating the drive database before investigating a warning and distinguishes Unverified from a drive tested Incompatible.

The migration guide has model, DSM, filesystem and package limitations and recommends backing up data and configuration first. Make a separate backup destination part of the order: Hyper Backup supports external storage, a remote NAS and cloud destinations. As a practical check, restore a sample file before starting the migration.

Complete and keep this dated purchase record:

• Checked date; exact enclosure; installed DSM/build/update.
• Drive part number; capacity; firmware; quantity; cache or pool role; fresh installation, replacement or migration.
• Saved compatible/incompatible lookup URLs and results; entry notes; applicable policy; accepted support limits.
• Installation or migration instructions; separate backup destination and restore check; final decision: buy / pause.

How we choose

We compare manufacturer specifications, Synology's policy and model-specific compatibility rows, including firmware notes. The HDD is a conditional starting candidate; the SSD example demonstrates a documented stop condition. Existing owner-verified product records supply the enclosure and HDD cards. Performance, noise and reliability rankings are outside this documentation-based comparison. See How we choose.

Verdict

Buy only when the enclosure, installed DSM, exact drive, firmware, capacity and role form a resolved order. Start a SATA HDD search with WD80EFPX; use SNV5420-800G only after its model-specific requirements are satisfied. Save the lookup and policy with your order so a later substitution or migration triggers a fresh check.