Main trade-off
ASUSTOR Nimbustor 2 Gen2
ADM is a different software environment from DSM.
Head-to-head
ASUSTOR AS5402T vs Synology DS225+: ASUSTOR adds SSD storage without giving up the two-drive mirror
The short answer
Choose AS5402T if you want mirrored hard drives plus separate NVMe storage, more memory headroom or two 2.5GbE ports. Choose DS225+ when Synology Photos and DSM backups are the reason for buying. Both have two SATA bays, but Synology has no M.2 slots and ships with less memory.
Before you choose
The reasoning and the trade-offs
Two mirrored hard drives leave different SSD options
After installing two hard drives, DS225+ has no unused internal drive positions for an SSD. AS5402T still has four NVMe slots. That matters if you want a separate SSD app volume while keeping the full hard-drive mirror.
What this is based on
DS225+: 2 SATA positions - 2 hard drives = 0 free positions, with no M.2. AS5402T retains its 4 separate M.2 positions after filling 2 SATA bays.
Main trade-off
Synology DiskStation DS225+
No M.2 slots and a 6 GB official memory ceiling.
ASUSTOR Nimbustor 2 Gen2
- Choose it for
- Keep two hard drives while adding separate NVMe storage
- Allow more memory for several home-server applications
- Main trade-off
- ADM is a different software environment from DSM.
Synology DiskStation DS225+
- Choose it for
- Use Synology Photos and DSM backup tools
- Keep a simple two-drive storage plan in a narrower case
- Main trade-off
- No M.2 slots and a 6 GB official memory ceiling.
About this comparison
Compare ASUSTOR AS5402T and Synology DS225+ for family photos, mirrored hard drives and SSD apps. See the storage and memory costs behind each choice.
Choose AS5402T if you want mirrored hard drives plus separate NVMe storage, more memory headroom or two 2.5GbE ports. Choose DS225+ when Synology Photos and DSM backups are the reason for buying. Both have two SATA bays, but Synology has no M.2 slots and ships with less memory.
Winner by situation
Start with what you need it to do
I want a hard-drive mirror plus a separate NVMe volume
ASUSTOR has dedicated NVMe slots. DS225+ has none.
- ASUSTOR Nimbustor 2 Gen2
- Better fit
- Synology DiskStation DS225+
- Not suitable
Synology Photos is my preferred photo workflow
DS225+ runs DSM and Photos. Budget extra RAM for object recognition.
- ASUSTOR Nimbustor 2 Gen2
- Depends
- Synology DiskStation DS225+
- Better fit
My chosen apps require 8 GB of memory
ASUSTOR supports a suitable upgrade. Synology officially stops at 6 GB.
- ASUSTOR Nimbustor 2 Gen2
- Depends
- Synology DiskStation DS225+
- Not suitable
One 2.5GbE client is my main network requirement
Both provide a 2.5GbE port. The rest of the path must support that rate.
- ASUSTOR Nimbustor 2 Gen2
- Good
- Synology DiskStation DS225+
- Good
What matters in practice
The differences that matter
Two mirrored hard drives leave different SSD options
After installing two hard drives, DS225+ has no unused internal drive positions for an SSD. AS5402T still has four NVMe slots. That matters if you want a separate SSD app volume while keeping the full hard-drive mirror.
How we reached this conclusion
DS225+: 2 SATA positions - 2 hard drives = 0 free positions, with no M.2. AS5402T retains its 4 separate M.2 positions after filling 2 SATA bays.
Photos object recognition adds a memory purchase on Synology
Synology specifies at least 4 GB for Photos object recognition, while DS225+ ships with 2 GB. If that feature is part of the reason you choose DSM, include a supported memory upgrade in the price comparison.
How we reached this conclusion
The current DS225+ software notes require a minimum of 4 GB for object recognition. Installed memory is 2 GB, below that threshold.
An 8 GB memory requirement rules out the official Synology ceiling
If the total requirements of your selected applications genuinely need 8 GB of RAM, DS225+ cannot meet that within its documented 6 GB maximum. AS5402T can, after a compatible upgrade. More RAM alone does not guarantee the CPU can run the workload.
How we reached this conclusion
8 GB exceeds the DS225+ official maximum of 6 GB. AS5402T supports up to 16 GB. Both ship below 8 GB.
Choice A
ASUSTOR, AS5402T
ASUSTOR Nimbustor 2 Gen2
The chassis has 2-bay storage. Its fastest documented network path is 2.5 Gbps.
- Best matched use
- Keep two hard drives while adding separate NVMe storage
Checked facts
- SATA drive bays: 2
- M.2 NVMe positions: 4
- Installed memory: 4 GB
- Official maximum memory: 16 GB
Choice B
Synology, DS225+
Synology DiskStation DS225+
The chassis has 2-bay storage. Its fastest documented network path is 2.5 Gbps.
- Best matched use
- Use Synology Photos and DSM backup tools
Checked facts
- SATA drive bays: 2
- M.2 NVMe positions: None
- Installed memory: 2 GB
- Official maximum memory: 6 GB
Meaningful differences
What changes the fit
| What changes | ASUSTOR Nimbustor 2 Gen2 | Synology DiskStation DS225+ | Why it matters |
|---|---|---|---|
| SATA drive bays | 2 | 2 | Both support a two-drive mirror, with usable capacity based on the smaller drive. |
| M.2 NVMe positions | 4 | None | ASUSTOR can add compatible NVMe devices without occupying a SATA bay. |
| Installed memory | 4 GB | 2 GB | ASUSTOR starts with twice the RAM, which is capacity rather than a performance guarantee. |
| Official maximum memory | 16 GB | 6 GB | The upgrade ceilings differ for memory-heavy applications. |
| Built-in network ports | Two 2.5GbE | One 2.5GbE and one 1GbE | Both can serve one 2.5GbE connection. The second port differs. |
| Software environment | ASUSTOR ADM | Synology DSM with Photos and backup packages | Choose the applications and administration workflow you intend to use. |
What you give up
Every choice has a cost
If you choose ASUSTOR Nimbustor 2 Gen2
- More slots and RAM support only help if the workload uses them.
If you choose Synology DiskStation DS225+
- Photos object recognition needs more RAM than the supplied 2 GB.
Recommendation switch
The decision flips if...
I need NVMe storage without giving up either hard drive
Choose ASUSTOR Nimbustor 2 Gen2. AS5402T has four dedicated NVMe positions.
My priority is the Synology Photos and backup workflow
Choose Synology DiskStation DS225+. DS225+ provides DSM, with the documented memory requirement for object recognition.
I need an internal four-hard-drive array
Choose neither. Both have only two SATA bays.
What matters in practice
How to make the call
Make the software preference specific
Choosing DSM is easier to justify when you know which Photos, Drive or backup feature you want. If the plan is mostly file sharing and a few self-hosted services, compare the hardware requirements of those services instead. A familiar interface and spare hardware capacity solve different problems.
Avoid using a SATA SSD to solve the wrong limitation
DS225+ can use compatible SATA SSDs in its main bays, but those are the same two positions needed for a hard-drive mirror. Replacing a hard drive with an SSD changes the storage layout. ASUSTOR's separate NVMe slots let you keep both hard drives in place while planning an SSD workload.
Leave room in the budget for a second copy
A two-drive mirror helps the NAS keep operating through one drive failure. It does not protect against every accidental deletion, theft or destructive event. Include a separate backup destination and test recovery. Extra RAM or SSDs should not consume the part of the budget needed to protect irreplaceable files.
What this comparison cannot tell you
- Storage calculations use equal-capacity compatible drives and decimal TB before formatting, system space and metadata. RAID protects against specified drive failures but does not replace a separate backup.
- Network figures are link rates rather than measured file-transfer speeds. Software support, memory revision, drive compatibility and the rest of the network must be checked for the exact purchase.
What the facts say
What the comparison shows
Useful conclusions from the current NAS devices comparison, followed by the checked facts used to reach them.
See the checked facts and calculation notes
| Product | Needs matched | Checked facts | Source records |
|---|---|---|---|
| ASUSTOR Nimbustor 2 Gen2 |
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| Synology DiskStation DS225+ |
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Ready to choose?
Check the price. Read the owner reviews.
Open either model on Amazon to check the current price, customer reviews and delivery options.
ASUSTOR Nimbustor 2 Gen2
Keep two hard drives while adding separate NVMe storage
See price & reviews on AmazonSynology DiskStation DS225+
Use Synology Photos and DSM backup tools
See price & reviews on AmazonLinks open in a new tab.