Who this build is for
- Several computers plus a growing family photo/video library
- Buyers who want one open bay for planned expansion
- Households prepared to run a second local or off-site backup target
Why this NAS and tier win
DS925+ is recommended here for DSM, four bays, ECC memory, dual 2.5GbE, and backup administration, not because its Ryzen V1500B is class-leading. Android Central praises the software and familiar reliability while criticizing hardware value and the original drive restriction. That criticism remains part of the decision even after DSM 7.3 restored third-party SATA pool creation. [1][2][3]
Starting with three drives avoids the common mistake of buying a four-bay NAS and immediately removing every expansion option. At equal drive sizes, three disks with one-drive redundancy provide two drive-equivalents of usable capacity. The fourth bay can later extend the pool after compatibility and backup checks. [4][5]
Why these exact drives
ST12000VN0008 is an exact 12TB CMR IronWolf model. Three drives target 24TB decimal usable, a large jump over entry without the price and acoustic footprint of an eight-bay Pro array. [6]
Third-party SATA support under DSM 7.3 is policy evidence, not an eternal compatibility promise. Check the exact DS925+ row, installed DSM release, seller, condition, firmware, and warranty at purchase. [4][3][5]
Capacity and protection plan
3 equal 12TB drives with 1 drive-equivalent reserved for redundancy produce an editorial planning estimate of 24TB decimal usable before formatting, filesystem metadata, snapshots, applications, and free-space reserve.
The three-drive pool can continue after one drive fails and leaves one bay open; RAID is not a backup. Reconfirm the RAID/SHR/RAIDZ behavior for the exact operating system and chosen disk layout before initialization.
What YouTube and community evidence change
The DS925+ review audience strongly values DSM but remains skeptical of conservative hardware and ecosystem control. The high engagement around specialist reviews is a reason to keep the policy caveat prominent rather than present Synology as an uncontested winner. [7][2]
Community drive testing after DSM 7.3 provides practical corroboration that third-party pools work, but it cannot replace the model-specific compatibility list or vendor support terms. [5]
Trade-offs before buying
Recommended setup sequence
- 1Estimate five years of backup growth and confirm that 24TB still leaves roughly 20% free.
- 2Install current DSM before creating the third-party-drive pool and capture the compatibility evidence.
- 3Create separate snapshot schedules for documents, photos, and computer-backup repositories.
- 4Use the open bay only after confirming the independent backup is current and tested.
- 5Send Hyper Backup to a separate USB disk, cloud target, or second-site NAS.
Alternatives worth considering
Lower enclosure cost, but less ECC/memory headroom and no expansion unit support.
AS5404T for stronger hardware valueAS5404TMore hardware for the money and fewer ecosystem restrictions, but a weaker cross-source consensus for easy household backup administration.
Frequently asked questions
Why use only three drives in a four-bay NAS?
Three equal drives provide one-drive redundancy and leave a bay for growth. Filling every bay immediately removes the easiest expansion path.
Can DS925+ use Seagate drives now?
DSM 7.3 restored third-party SATA pool creation, but exact model support and troubleshooting terms can change. Recheck the live compatibility list immediately before buying.
Is 24TB the displayed capacity?
No. It is a decimal planning figure before filesystem, system, snapshot, and reserve overhead. The operating system will show a lower binary capacity.
Sources and evidence boundary
This article synthesizes official product facts, independent reviews, YouTube material, and community discussion. YouTube view/like/comment counts are a dated engagement signal, not a quality score. Community posts are anecdotal and cannot establish failure rates. Reviewers may use affiliate links; one publisher’s article and companion video count as one editorial viewpoint.
Synology · accessed Aug 31, 2026. Four bays, Ryzen V1500B, ECC memory, dual 2.5GbE and expansion support.
Android Central · Apr 23, 2025 · accessed Aug 31, 2026. Finds class-leading software and reliable direct-play media service, but no hardware transcoding and poor hardware value; original drive-policy criticism predates DSM 7.3.
Tom's Hardware · Oct 9, 2025 · accessed Aug 31, 2026. Documents restored third-party 3.5-inch HDD and 2.5-inch SATA SSD use while M.2 pool rules remain tighter.
Synology Knowledge Center · accessed Aug 31, 2026. DSM 7.3 policy context for third-party SATA drives; exact MPN compatibility still requires purchase-time checking.
Reddit r/synology · accessed Aug 31, 2026. User reports of third-party drive behavior after DSM 7.3, treated as anecdotal policy corroboration.
Engagement at capture: 67-point thread at research capture.
Seagate · accessed Aug 31, 2026. NAS-oriented CMR family; exact 4TB and 12TB MPN facts are stored in the ChooseCompute catalog.
NASCompares · May 2, 2025 · accessed Aug 31, 2026. Detailed model review; shares an editorial publisher with NASCompares articles and is not counted as an independent second vote.
Engagement at capture: 54,207 views; 1,293 likes; 459 comments at capture.