The catch
ASUSTOR Nimbustor 2 Gen2
The internal hard-drive array is held back by having two SATA bays.
Side by side
ASUSTOR AS5402T vs AS5404T: Four NVMe slots on each, though only 5404T holds four hard drives
Quick verdict
If two hard drives cover your storage plan and you want the narrower case, go with the AS5402T. For a larger hard-drive array, or two-drive fault tolerance with RAID 6, go with the AS5404T. Four NVMe slots, the same processor family and dual 2.5GbE come on both already, so none of those features calls for the larger chassis.
Before you buy
Why, and what it costs you
Capacity with one-drive protection can triple with four hard drives
Take compatible equal 12 TB drives. Two-drive RAID 1 gives 12 TB before overhead, and four-drive RAID 5 gives 36 TB. That means AS5404T delivers three times the illustrative usable capacity and still tolerates one drive failure, though you pay for two more drives.
Where this comes from
For RAID 1, 2 × 12 TB mirrored = 12 TB. For RAID 5, (4 - 1) × 12 TB = 36 TB. 36 / 12 = 3. A separate backup is still necessary.
The catch
ASUSTOR Nimbustor 4 Gen2
The chassis runs 60 mm wider.
ASUSTOR Nimbustor 2 Gen2
- Why pick it
- Stay with two hard drives in a narrower case
- Put together an NVMe project with no extra SATA bays to buy
- The catch
- The internal hard-drive array is held back by having two SATA bays.
ASUSTOR Nimbustor 4 Gen2
- Why pick it
- Set up a larger protected array of three or four hard drives
- Run RAID 6 protection across four hard drives
- The catch
- The chassis runs 60 mm wider.
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What this page compares
Family storage, Plex and SSD projects on ASUSTOR AS5402T vs AS5404T. Two extra hard-drive bays change usable capacity, but they add no faster networking.
If two hard drives cover your storage plan and you want the narrower case, go with the AS5402T. For a larger hard-drive array, or two-drive fault tolerance with RAID 6, go with the AS5404T. Four NVMe slots, the same processor family and dual 2.5GbE come on both already, so none of those features calls for the larger chassis.
Which one fits
Pick the situations that sound like you
My capacity needs are covered by two mirrored hard drives
That layout fits AS5402T, which has a narrower enclosure.
- ASUSTOR Nimbustor 2 Gen2
- Better fit
- ASUSTOR Nimbustor 4 Gen2
- Good
I plan on RAID 6 across four hard drives
The four SATA bays that internal hard-drive array needs are on AS5404T.
- ASUSTOR Nimbustor 2 Gen2
- Not suitable
- ASUSTOR Nimbustor 4 Gen2
- Better fit
I plan on four NVMe drives
Four M.2 positions are on each. Check which drives are compatible and what storage configuration you intend.
- ASUSTOR Nimbustor 2 Gen2
- Good
- ASUSTOR Nimbustor 4 Gen2
- Good
Speed per Ethernet port is what I want to raise
Each supplies 2.5GbE ports, and the larger chassis does not raise their link rate.
- ASUSTOR Nimbustor 2 Gen2
- Similar
- ASUSTOR Nimbustor 4 Gen2
- Similar
In practice
Differences you will notice
Capacity with one-drive protection can triple with four hard drives
Take compatible equal 12 TB drives. Two-drive RAID 1 gives 12 TB before overhead, and four-drive RAID 5 gives 36 TB. That means AS5404T delivers three times the illustrative usable capacity and still tolerates one drive failure, though you pay for two more drives.
How we worked this out
For RAID 1, 2 × 12 TB mirrored = 12 TB. For RAID 5, (4 - 1) × 12 TB = 36 TB. 36 / 12 = 3. A separate backup is still necessary.
The hard-drive plan shifts with two-drive protection
RAID 6 across four 12 TB hard drives gives 24 TB before overhead and tolerates two drive failures. AS5402T cannot build that four-hard-drive array internally. The four NVMe slots on it are a separate storage option and do not count as extra hard-drive bays.
How we worked this out
Usable capacity for RAID 6 is (4 - 2) × 12 TB = 24 TB. SATA bays number 2 on one model and 4 on the other.
The bigger model gives an all-NVMe plan no extra slots
For a project that uses only NVMe drives, both models have four positions. The four-bay version is 60 mm wider in the case and has no more slots for it. The smaller chassis can therefore handle the same four-NVMe layout.
How we worked this out
4 NVMe slots on both models, while AS5404T has 174 - 114 = 60 mm more case width.
Option A
ASUSTOR, AS5402T
ASUSTOR Nimbustor 2 Gen2
A 2-bay chassis whose fastest documented network path is 2.5 Gbps.
- Best for
- Stay with two hard drives in a narrower case
Facts we checked
- SATA bays inside: 2
- NVMe slots: 4
- Processor: Intel Celeron N5105
- Installed / maximum RAM: 4 GB / 16 GB
Option B
ASUSTOR, AS5404T
ASUSTOR Nimbustor 4 Gen2
A 4-bay chassis whose fastest documented network path is 2.5 Gbps.
- Best for
- Set up a larger protected array of three or four hard drives
Facts we checked
- SATA bays inside: 4
- NVMe slots: 4
- Processor: Intel Celeron N5105
- Installed / maximum RAM: 4 GB / 16 GB
Spec by spec
Where they really differ
| Spec | ASUSTOR Nimbustor 2 Gen2 | ASUSTOR Nimbustor 4 Gen2 | In practice |
|---|---|---|---|
| Internal SATA bays | 2 | 4 | More hard drives can go into a single internal array on the larger model. |
| NVMe slots | 4 | 4 | Stepping up brings no extra NVMe positions. |
| Processor | Intel Celeron N5105 | Intel Celeron N5105 | Both use the same CPU specification. A higher model number does not show more transcoding capacity. |
| Installed / maximum RAM | 4 GB / 16 GB | 4 GB / 16 GB | The official memory ceiling is identical on both. |
| Built-in Ethernet | Two 2.5GbE ports | Two 2.5GbE ports | Moving up leaves the speed of each individual network port unchanged. |
| Case width | 114 mm | 174 mm | In the datasheets, height and depth match and the four-bay chassis needs 60 mm more width. |
Trade-offs
What each pick costs you
With ASUSTOR Nimbustor 2 Gen2
- Growing the hard-drive pool later may mean replacing the enclosure.
With ASUSTOR Nimbustor 4 Gen2
- It brings no extra NVMe slots, RAM ceiling or faster built-in Ethernet.
Change of plan
When the answer changes
I'm after four internal hard drives
Go with ASUSTOR Nimbustor 4 Gen2. Four SATA bays are found only on AS5404T.
I want four NVMe slots and at most two SATA drives
Go with ASUSTOR Nimbustor 2 Gen2. That slot layout fits AS5402T in a narrower case.
I require native 10GbE
Neither model fits. Built-in Ethernet is 2.5GbE on both, not 10GbE.
Decision guide
How to decide
Settle the protected capacity first, then the enclosure
Begin with the files you must keep, how much you expect them to grow and a separate backup copy. For a household, two large mirrored hard drives may be enough. A video archive that keeps growing can make four bays the cheaper way to expand, though you are then buying more drives and a wider case.
Plan hard drives and NVMe on separate tracks
From its name, the AS5402T might seem limited to two storage devices, yet it also has four NVMe positions. Those slots suit compatible SSD storage or caching, but they cannot take large SATA hard drives. Work out which medium your workload needs before leaning on total slot count.
More bays will not fix a slow network
Dual 2.5GbE comes on both models. A computer that still goes through a 1GbE switch stays limited by that path. Extra drives may help a storage workload, but the slow network segment will not go away. Before paying for a larger chassis to fix a transfer-speed problem, check the client, switch and cabling.
What this page can’t tell you
- Storage figures assume compatible drives of equal capacity and decimal TB, counted before formatting, system space and metadata. RAID covers the drive failures it is specified for, but it does not replace a separate backup.
- Treat network figures as link rates. They are not measured file-transfer speeds. For the exact model you buy, check software support, memory revision, drive compatibility and the rest of the network.
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 |
|---|---|---|---|
| ASUSTOR Nimbustor 2 Gen2 |
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| ASUSTOR Nimbustor 4 Gen2 |
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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.
ASUSTOR Nimbustor 2 Gen2
Stay with two hard drives in a narrower case
See price & reviews on AmazonASUSTOR Nimbustor 4 Gen2
Set up a larger protected array of three or four hard drives
See price & reviews on AmazonEach link opens in a new tab.
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