The catch
TerraMaster F4-425
That single network port is capped at 2.5GbE.
Side by side
TerraMaster F4-425 vs Synology DiskStation DS425+ Compared: Four hard drives can sit next to supported M.2 storage on Synology
Quick verdict
Straightforward SATA storage with 4GB memory is what the F4-425 includes. The DS425+ is the choice once DSM applications and its two M.2 slots are part of your purchase requirements.
Before you buy
Why, and what it costs you
Protected capacity when all drives are 12TB
Before formatting, this example gives 36TB with F4-425 and 36TB with Synology DiskStation DS425+. A different chassis does not increase protected capacity.
Where this comes from
Suppose each SATA bay holds a supported 12TB disk. A two-bay RAID 1 gives the usable capacity of one disk. With three or more drives, RAID 5 usable TB = (drive count minus 1) × 12. The layout is only an illustration. It is not storage that comes included, and it is not a backup.
The catch
Synology DiskStation DS425+
Many apps will find the 2GB base memory modest.
TerraMaster F4-425
- Why pick it
- A SATA archive with 4GB supplied RAM is what you want
- supported ram ceiling: you want 16GB
- The catch
- That single network port is capped at 2.5GbE.
Synology DiskStation DS425+
- Why pick it
- DSM and a supported M.2 storage role are what you want
- supported ram ceiling: you want 6GB
- The catch
- Many apps will find the 2GB base memory modest.
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What this page compares
Which of F4-425 and DS425+ fits depends on protected storage, included networking and the exact SSD or application layout you need.
The question is a SATA archive or the DSM storage ecosystem.
Which one fits
Pick the situations that sound like you
Protected archive built from 12 TB disks filling every internal SATA bay
This example uses RAID 1 for two disks and RAID 5 for three or more. F4-425 comes to 36TB and Synology DiskStation DS425+ to 36TB before formatting. A different chassis leaves this protected capacity where it is.
- TerraMaster F4-425
- Similar
- Synology DiskStation DS425+
- Similar
A workstation already at the speed of the faster included Ethernet port
The ports included run at 2.5GbE and 2.5GbE. Read the 100GB calculation together with the real client speed.
- TerraMaster F4-425
- Similar
- Synology DiskStation DS425+
- Similar
Multiple local services dividing up the supplied RAM
TerraMaster F4-425 ships with 4 GB RAM and supports 16 GB, while Synology DiskStation DS425+ ships with 2 GB and supports 6 GB. Weigh the stated application memory requirement against the supplied configuration before you budget for an upgrade. A larger RAM capacity is not proof of application speed.
- TerraMaster F4-425
- Better fit
- Synology DiskStation DS425+
- Depends
Add a supported M.2 SSD mirror and still keep four SATA hard drives
Because the DS425+ has two M.2 positions, a mirrored pool of two SSDs can sit there and leave all four SATA bays to HDDs, provided supported Synology SSDs are used. With no M.2 positions, the F4-425 would use up SATA bays for that SSD layout.
- TerraMaster F4-425
- Not suitable
- Synology DiskStation DS425+
- Better fit
In practice
Differences you will notice
Protected capacity when all drives are 12TB
Before formatting, this example gives 36TB with F4-425 and 36TB with Synology DiskStation DS425+. A different chassis does not increase protected capacity.
How we worked this out
Suppose each SATA bay holds a supported 12TB disk. A two-bay RAID 1 gives the usable capacity of one disk. With three or more drives, RAID 5 usable TB = (drive count minus 1) × 12. The layout is only an illustration. It is not storage that comes included, and it is not a backup.
100GB moved at the speed ceiling of the included port
At line rate, the minimum is 320 seconds for F4-425 and 320 seconds for Synology DiskStation DS425+. Real copies take longer. With a 1GbE client the lower bound becomes 800 seconds for both.
How we worked this out
Decimal 100GB × 8 = 800 gigabits. Take the fastest included port rate, 2.5Gbps or 2.5Gbps, and divide 800 by it. Protocol overhead is ignored here only because this is a lower-bound calculation. Optional adapters and aggregated ports are left out.
Find out if the SSD plan means cache or primary storage
Because the DS425+ has two M.2 positions, a mirrored pool of two SSDs can sit there and leave all four SATA bays to HDDs, provided supported Synology SSDs are used. With no M.2 positions, the F4-425 would use up SATA bays for that SSD layout.
How we worked this out
For DS425+, 2 M.2 positions minus 2 SSDs = 0 spare M.2, and all 4 SATA positions are preserved. For F4-425, 4 SATA positions minus 2 SSDs = 2 left for HDDs. The documented M.2 pool path requires Synology-verified SSDs.
Option A
TerraMaster, F4-425
F4-425
Compared with a two-bay mirror, four SATA bays leave a growing archive more RAID layouts to choose from. Having a single 2.5GbE port and 4GB memory keeps the specs aimed at file storage.
- Best for
- A family archive that is growing, on four drives
Facts we checked
- 0 M.2 slots alongside 4 SATA drive bays
- Fastest network port included: 2.5GbE
- Comes with 4GB of RAM, expandable to 16GB
- Intel N5095 processor in a diskless NAS
Option B
Synology, DS425+
Synology DiskStation DS425+
A 4-bay chassis whose fastest documented network path is 2.5 Gbps.
- Best for
- keep family photos safe on a four-drive starting setup
Facts we checked
- Storage fits in a 4-bay chassis.
- The fastest network path documented for it runs at 2.5 Gbps.
- It supports serving media through Plex.
- Camera recording works, though how many channels you can license depends on the software and plan you choose.
Spec by spec
Where they really differ
| Spec | TerraMaster F4-425 | Synology DiskStation DS425+ | In practice |
|---|---|---|---|
| Supplied RAM | 4GB | 2GB | This figure is the memory already installed, before any upgrade modules are bought. |
| Supported RAM ceiling | 16GB | 6GB | The manufacturer-supported upgrade ceiling for concurrent services is set by this. |
| M.2 storage slots | 0 | 2 | Treat SSD cache and storage pools as a separate plan from the SATA archive. |
| Processor | Intel N5095 | Intel Celeron J4125 | The platform determines the media engines, the application architecture and the concurrency. |
| Software and expansion route | TOS | DSM | Pick the applications and supported add-ons the job calls for. |
Trade-offs
What each pick costs you
With TerraMaster F4-425
- The listing shows no M.2 storage slots, and because the enclosure is diskless you need to budget for drives separately.
With Synology DiskStation DS425+
- 10GbE is not available as an upgrade.
Change of plan
When the answer changes
A SATA archive with 4GB supplied RAM is what you want
Go with TerraMaster F4-425. F4-425 comes with 4 GB and supports 16 GB, and all four SATA bays stay available to the archive. Since it has no M.2 positions, any internal SSD plan has to take SATA bays.
DSM and a supported M.2 storage role are what you want
Go with Synology DiskStation DS425+. DS425+ runs DSM and has two M.2 positions. Before you expect an SSD mirror next to four hard drives, confirm the exact supported SSD and pool role.
Decision guide
How to decide
First, pin down the storage layout you need
Straightforward SATA storage with 4GB memory is what the F4-425 includes. The DS425+ is the choice once DSM applications and its two M.2 slots are part of your purchase requirements.
Count what the drive budget allows
RAID capacity is basically the same with four equal hard drives. The DS425+ does not earn extra archive space just for having M.2 slots, and their storage-pool compatibility has to be checked separately.
Look at the client and apps you will really use
More installed memory is supported on the F4-425, whereas the DS425+ comes with SSD compatibility rules specific to Synology. Before ordering drives, confirm the exact SSD model and the caching or storage role you intend for it.
What this page can’t tell you
- Capacity examples assume equal 12TB drives, counted before formatting, snapshots and filesystem overhead.
- Treat Ethernet calculations as lower bounds, since disk performance, network protocol and other traffic add time.
- Neither application speed nor a VM count follows from memory capacity alone.
By the numbers
What the data shows
What we found across the NAS devices we compare, plus the checked facts behind each finding.
How many fit
Only 8 of the 32 models checked meet every need here: “Four drives to start” and “Keep going after one drive fails”.
8 models fit, out of 32 checkedShow the facts and the math
How we countedThe count uses each product's current fit ratings for “Four drives to start” and “Keep going after one drive fails”. A need with no documented match is not counted.
| Product | Needs it meets | Facts we checked | Sources |
|---|---|---|---|
| TerraMaster F4-425 |
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| Synology DiskStation DS425+ |
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Ready to buy
See today’s price and what owners say
Open either model on Amazon for the current price, customer reviews and delivery options.
TerraMaster F4-425
A SATA archive with 4GB supplied RAM is what you want
See price & reviews on AmazonSynology DiskStation DS425+
DSM and a supported M.2 storage role are what you want
See price & reviews on AmazonEach link opens in a new tab.
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