The catch
Synology DiskStation DS925+
Each link on the included network ports tops out at 2.5GbE.
Side by side
Synology DS925+ vs TerraMaster F4-425 Plus Compared: Synology offers a separate path to expand bays, with the same starting HDD capacity
Quick verdict
A growing archive that can use Synology's documented DX525 expansion route and ECC memory points to the DS925+. If dual 5GbE, three M.2 slots and 16GB supplied memory solve your current workstation setup, the F4-425 Plus is the pick. Four SATA bays are the starting point on both, so identical drive and RAID choices give the same protected capacity whichever brand you buy.
Before you buy
Why, and what it costs you
The storage math starts out the same with four equal drives
On either model, four equal 8TB drives in RAID 5 give about 24TB before overhead. RAID 6 leaves about 16TB instead and tolerates two drive failures.
Where this comes from
For four-drive RAID 5 the sum is (4 minus 1) × 8TB, and for RAID 6 it is (4 minus 2) × 8TB. These capacity examples leave out formatting, system space and retained versions.
The catch
TerraMaster F4-425 Plus N150 16GB
Another SATA archive bay does not come from the third M.2 slot.
The DS925+ appears here with the optional DX525 expansion unit. Drives and the DX525 are sold separately.
Synology DiskStation DS925+
- Why pick it
- Bring in a supported DX525 once you need more SATA bays
- Get a system that ships with ECC memory
- The catch
- Each link on the included network ports tops out at 2.5GbE.
TerraMaster F4-425 Plus N150 16GB
- Why pick it
- Take the included 5GbE links and three M.2 slots
- Begin on the selected N150 configuration with 16GB
- The catch
- Another SATA archive bay does not come from the third M.2 slot.
We may earn a commission from qualifying Amazon purchases. How we make money
What this page compares
Four-drive backup storage, future SATA expansion and a 5GbE workstation: how DS925+ and the N150 F4-425 Plus differ.
A growing archive that can use Synology's documented DX525 expansion route and ECC memory points to the DS925+. If dual 5GbE, three M.2 slots and 16GB supplied memory solve your current workstation setup, the F4-425 Plus is the pick. Four SATA bays are the starting point on both, so identical drive and RAID choices give the same protected capacity whichever brand you buy.
Which one fits
Pick the situations that sound like you
One included 5GbE workstation connection is needed
Ports on DS925+ negotiate up to 2.5GbE, and TerraMaster includes 5GbE.
- Synology DiskStation DS925+
- Caution
- TerraMaster F4-425 Plus N150 16GB
- Better fit
Plan on a supported DX525 for SATA expansion
The documented expansion route specific to Synology is DX525.
- Synology DiskStation DS925+
- Better fit
- TerraMaster F4-425 Plus N150 16GB
- Not suitable
ECC memory required
DDR4 ECC is explicitly supplied by Synology, while the TerraMaster listing does not establish equivalent system ECC.
- Synology DiskStation DS925+
- Better fit
- TerraMaster F4-425 Plus N150 16GB
- Caution
Run a configuration with 16GB of supplied memory
TerraMaster comes with 16GB, and DS925+ comes with 4GB and needs an upgrade to reach that amount.
- Synology DiskStation DS925+
- Caution
- TerraMaster F4-425 Plus N150 16GB
- Better fit
In practice
Differences you will notice
The storage math starts out the same with four equal drives
On either model, four equal 8TB drives in RAID 5 give about 24TB before overhead. RAID 6 leaves about 16TB instead and tolerates two drive failures.
How we worked this out
For four-drive RAID 5 the sum is (4 minus 1) × 8TB, and for RAID 6 it is (4 minus 2) × 8TB. These capacity examples leave out formatting, system space and retained versions.
A faster workstation needs a fast path end to end
F4-425 Plus comes with 5GbE sockets and DS925+ with 2.5GbE sockets. TerraMaster is the choice if a single 5GbE client path is already planned and the storage workload gains from removing that link-rate ceiling.
How we worked this out
This comparison is about one Ethernet connection. Adding up two 2.5GbE ratings does not produce a single 5GbE connection unless a multichannel setup is separately supported.
A RAM label is not a promise of reliability or speed
DS925+ comes with 4GB ECC memory, while this F4-425 Plus listing comes with 16GB DDR5.
How we worked this out
Both the quantity and the type of supplied memory differ. The TerraMaster listing has to stay the N150 16GB variant and not a different selectable configuration.
Option A
The DS925+ appears here with the optional DX525 expansion unit. Drives and the DX525 are sold separately.
Synology, DS925+
Synology DiskStation DS925+
This is a 4-bay chassis, and 2.5 Gbps is the fastest network path documented for it.
- Best for
- Bring in a supported DX525 once you need more SATA bays
Facts we checked
- SATA bays inside: Four
- Ethernet supplied: Two 2.5GbE ports
- Memory included: 4GB DDR4 ECC
- M.2 slots: Two
Option B
TerraMaster, F4-425 Plus N150 16GB
F4-425 Plus N150 16GB
A bulk array and SSD-backed applications both fit here, thanks to four SATA bays, three M.2 slots and 16GB supplied memory. Dual 5GbE ports are a good match for an upgraded home or small-office network.
- Best for
- Take the included 5GbE links and three M.2 slots
Facts we checked
- SATA bays inside: Four
- Ethernet supplied: Two 5GbE ports
- Memory included: 16GB DDR5
- Slots for M.2: Three
Spec by spec
Where they really differ
| Spec | Synology DiskStation DS925+ | TerraMaster F4-425 Plus N150 16GB | In practice |
|---|---|---|---|
| Internal SATA bays | Four | Four | Nominal capacity begins at the same figure for the same equal-drive RAID layout. |
| Included Ethernet | Two 2.5GbE ports | Two 5GbE ports | TerraMaster is favored by a single 5GbE workstation link. |
| Supplied memory | 4GB DDR4 ECC | 16GB DDR5 | Error correction and memory quantity are separate attributes. |
| M.2 slots | Two | Three | On TerraMaster, a two-SSD mirror still leaves one extra onboard SSD slot. |
| SATA expansion plan | One DX525 supports nine bays in total | Four internal SATA bays, separate USB DAS options require their own plan | A specific five-bay expansion accessory is documented by Synology. |
Trade-offs
What each pick costs you
With Synology DiskStation DS925+
- An additional purchase is needed to reach a 16GB memory plan.
With TerraMaster F4-425 Plus N150 16GB
- Synology's DX525 integration is not automatically matched by a separate USB enclosure.
Change of plan
When the answer changes
Growth of the archive has to go through a supported DX525
Go with Synology DiskStation DS925+. That named expansion unit is supported by DS925+.
For the immediate setup, 5GbE and 16GB supplied memory are required
Go with TerraMaster F4-425 Plus N150 16GB. Both come with the selected N150 F4-425 Plus.
Decision guide
How to decide
The storage math starts out the same with four equal drives
Four equal 8TB drives in RAID 5 provide about 24TB before overhead on either model, while RAID 6 leaves about 16TB and tolerates two drive failures. Choose between these chassis for the surrounding workflow, not on a claim that faster networking creates more protected space. If the archive is likely to outgrow four drives, budget for the DS925+'s supported DX525 route before the first pool is filled.
A faster workstation needs a fast path end to end
5GbE sockets come with the F4-425 Plus, whereas the DS925+ has 2.5GbE sockets. Choose TerraMaster if a single 5GbE client path is already planned and the storage workload gains from lifting that link-rate ceiling. A Gigabit switch or adapter still limits either NAS on that leg. The DS925+ stays a sensible option when its storage expansion and DSM workflow matter more than a faster included port.
A RAM label is not a promise of reliability or speed
4GB ECC memory is what the DS925+ supplies, and this F4-425 Plus listing supplies 16GB DDR5. Choose Synology if ECC is an explicit hardware requirement, or TerraMaster if a documented application plan needs more than 4GB at installation. Neither label proves application capacity or overall data safety. You still need backups, and any later memory purchase should follow the manufacturer's approved configuration.
What this page can’t tell you
- No comparative test of reliability, application speed or transcoding is claimed. Backups are still needed with ECC memory.
By the numbers
What the data shows
What we found across the NAS devices we compare, plus the checked facts behind each finding.
Show the facts and the math
| Product | Needs it meets | Facts we checked | Sources |
|---|---|---|---|
| Synology DiskStation DS925+ |
|
| |
| TerraMaster F4-425 Plus N150 16GB |
|
|
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.
The DS925+ appears here with the optional DX525 expansion unit. Drives and the DX525 are sold separately.
Synology DiskStation DS925+
Bring in a supported DX525 once you need more SATA bays
See price & reviews on AmazonTerraMaster F4-425 Plus N150 16GB
Take the included 5GbE links and three M.2 slots
See price & reviews on AmazonEach link opens in a new tab.
We may earn a commission from qualifying Amazon purchases. How we make money