The buying guide
Package and specification details
Budget for drives with either enclosure
Neither package includes storage drives. TerraMaster lists the F4-425 unit, power cord and adapter, one RJ-45 cable, a quick guide, a warranty note and screws; the DS425+ listing includes the unit, an accessory pack, the AC adapter and cord and two LAN cables. Four bays are not four drives or a promise of usable capacity, and RAID is not a separate backup.
Sources · 2026-09-13
TerraMaster: F4-425 specification PDFChecked 2026-10-21. Read the original source and its check date before relying on this value.Synology: DiskStation DS425+ US hardware and software specificationsChecked 2026-09-13. We read the original webpage on the check date.B&H: Synology DS425+ US diskless enclosure listingChecked 2026-09-13. We read the original webpage on the check date.Review due. Check the current source before buying.
More memory at the start, different upgrade paths
The F4-425 ships with one 4 GB DDR4 non-ECC SODIMM in its only memory slot and lists 16 GB as the maximum, so reaching it means replacing the factory module. DS425+ has 2 GB onboard plus one slot, with a 6 GB maximum using Synology's D4NS01-4G module under its support conditions. TerraMaster says it may substitute factory memory of the same or higher frequency. More memory alone does not establish faster file serving or app performance.
Sources · 2026-09-13
TerraMaster: F4-425 4-Bay NAS: TerraMaster official store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.TerraMaster: F4-425 specification PDFChecked 2026-10-21. Read the original source and its check date before relying on this value.Synology: DiskStation DS425+ US hardware and software specificationsChecked 2026-09-13. We read the original webpage on the check date.Review due. Check the current source before buying.
M.2 slots and SSD cache
DS425+ has two M.2 2280 NVMe slots, and Synology requires drives on its compatibility list for M.2 storage pools and cache. TerraMaster's comparison table lists no M.2 slot for the F4-425, although its datasheet lists SSD cache support and 2.5-inch SATA SSDs among the drive types for its four bays. Check each maker's compatibility list for the exact drives and the role you plan for them.
Sources · 2026-09-13
TerraMaster: F4-425 Plus store page: four-model comparison tableChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.TerraMaster: F4-425 specification PDFChecked 2026-10-21. Read the original source and its check date before relying on this value.Synology: DiskStation DS425+ US hardware and software specificationsChecked 2026-09-13. We read the original webpage on the check date.Synology: DSM 7.3 drive-policy announcement for 2025 DiskStation modelsChecked 2026-09-13. We read the original webpage on the check date.Review due. Check the current source before buying.
Port ratings are not throughput
The F4-425 has one 2.5GbE port; DS425+ has one 2.5GbE port and one Gigabit port. TerraMaster's figure of up to 280 MB/s over 2.5GbE is its own claim, not a CompareFoundry measurement. Do not add the DS425+ port speeds together: the switch, client, drives, storage configuration and protocol all affect transfers.
Sources · 2026-09-13
TerraMaster: F4-425 4-Bay NAS: TerraMaster official store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.TerraMaster: F4-425 specification PDFChecked 2026-10-21. Read the original source and its check date before relying on this value.Synology: DiskStation DS425+ US hardware and software specificationsChecked 2026-09-13. We read the original webpage on the check date.Review due. Check the current source before buying.
Check the software, warranty and seller
The F4-425 uses TerraMaster's TOS software and is sold on TerraMaster's own store, whose shipping policy covers ground delivery within the continental United States; TerraMaster lists a 2-year limited warranty. The DS425+ route is a B&H listing for the standard diskless enclosure. Confirm drive compatibility, the operating-system version and the seller before buying; processor identity alone does not predict transcoding or app performance.
Sources · 2026-09-13
TerraMaster: F4-425 4-Bay NAS: TerraMaster official store pageChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.TerraMaster: F4-425 specification PDFChecked 2026-10-21. Read the original source and its check date before relying on this value.TerraMaster: TerraMaster store shipping policyChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.B&H: Synology DS425+ US diskless enclosure listingChecked 2026-09-13. We read the original webpage on the check date.Review due. Check the current source before buying.
Common questions
Does the TerraMaster F4-425 have M.2 SSD slots?
No M.2 slot is listed. TerraMaster's comparison table shows M.2 SSD Slot: None for the F4-425 and three M.2 slots for the separate F4-425 Plus. The F4-425's four bays take 3.5-inch and 2.5-inch SATA drives.
Sources · 2026-10-21
TerraMaster: F4-425 Plus store page: four-model comparison tableChecked 2026-10-21. We reviewed the official page text on the check date. Checkout options were not verified.TerraMaster: F4-425 specification PDFChecked 2026-10-21. Read the original source and its check date before relying on this value.Evidence limits
These manufacturer specifications do not establish measured performance, noise, long-term reliability or running cost. We have not independently tested these products. Check current prices, stock and operating-space instructions with the seller and manufacturer.
Product specifications and sources
- TerraMaster F4-425 specifications and purchase packages
- Synology DiskStation DS425+ specifications and purchase packages
These notes apply to the starting packages. Changing a selection opens your own comparison and hides the notes that no longer apply.
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