ASUSTOR NIMBUSTOR 4 Gen2 (AS5404T) four-bay NAS review

The ASUSTOR NIMBUSTOR 4 Gen2 (AS5404T) is a four-bay desktop NAS with two distinct storage layers: four 2.5- or 3.5-inch SATA positions and four M.2 NVMe slots. That split is the main reason to consider it over a conventional four-tray NAS; it is also a reason to slow down and check which drives belong in which interface. This is a source-based assessment of the manufacturer’s documentation, not a hands-on review, benchmark, or claim about a particular seller’s package.

Four SATA bays plus a separate M.2 layer

ASUSTOR’s U.S.-English AS5404T datasheet lists four 3.5- or 2.5-inch SATA HDD/SSD positions, plus four M.2 slots for NVMe SSDs. The model’s hardware specification gives more detail: M.2 2280 NVMe, on a PCIe 3.0 x1 interface. These are two different connection types. A buyer counting native SATA bays should count four, not eight, and should check exact M.2 drive compatibility separately.

The M.2 slots are not merely cosmetic. ASUSTOR describes them for cache, storage, or a combination, which may let an owner design a mixed HDD-and-flash layout. But slot count alone does not approve a specific SSD, firmware, cooling arrangement, or storage plan. The AS54-series quick-installation guide provides a separate installation section for M.2 SSDs and sends owners to ASUSTOR’s compatibility selector. If your plan is a four-drive SATA RAID plus four M.2 drives, verify the exact media and intended layout before buying rather than treating the published connector count as a complete bill of materials.

A mirror can leave two SATA positions open

ASUSTOR lists RAID 1 among the AS5404T’s volume types. Its RAID calculator includes the AS5404T as a recommended model and says a single RAID 1 volume supports at most two drives. A possible owner-created two-drive mirror therefore uses two of the four SATA bays and leaves two native SATA positions unused. That is a useful distinction from the two-bay AS5402T, where the same two-drive mirror occupies both SATA positions.

This is a possible operating plan, not a preconfigured feature delivered with the unit. The exact-model package contents page does not list data drives or a prepared array. Select drives only after checking their full model and firmware against ASUSTOR’s compatibility material. The quick-install guide warns that system initialization erases data; keep a separate backup before configuring storage. RAID 1 may help maintain access after one member drive fails, but it does not protect against deletion, malware, theft, fire, or damage to the entire NAS.

Two 2.5-Gigabit ports do not make one 5-Gbps port

The datasheet lists two separate 2.5-Gigabit Ethernet ports. For a one-port requirement, the relevant maximum is 2.5 Gbps, not 5 Gbps. ASUSTOR advertises up to 5 Gbps using SMB Multichannel when compatible links and endpoints are combined. That is a conditional multi-link arrangement, not a single faster jack or an observed file-transfer result. A router or switch, client, cable, storage media, software configuration, and workload can all constrain the complete path.

ASUSTOR also publishes laboratory figures for sequential reads and writes on an optimized SMB Multichannel setup. Those vendor figures are not a promise that a home network will reproduce them, and this assessment has not independently tested them. If a single-client 2.5-Gigabit link is the goal, check that the switch or router and client interface also support that rate. If you intend to use multiple links, confirm the endpoint and SMB configuration instead of adding the two port ratings on paper.

Hardware and local-media claims need context

The listed processor is a quad-core Intel Celeron N5105, with 4 GB of DDR4-2933 memory and a manufacturer-listed 16-GB maximum across two memory slots. The AS54-series guide explains how to reach the memory compartment, but it cautions that third-party memory is not guaranteed and advises owners unfamiliar with computer memory upgrades not to install a module themselves. The headline maximum is therefore not an assurance that any module or upgrade will work.

Other connections include three USB 3.2 Gen 2 ports and HDMI 2.0b. ASUSTOR describes local 4K video features on the product page, but the HDMI socket alone does not confirm a particular app, codec, television, or media-library workflow. Those software and format checks matter if local playback or transcoding is your reason for choosing this unit.

The manufacturer lists a 90-W AC adapter, dimensions of 170 × 174 × 230 mm (H × W × D), and a 2.26-kg chassis weight. Its published reference power figures are 38.3 W in operation, 17.7 W during disk hibernation, and 0.81 W in sleep mode; ASUSTOR also lists 19.7 dB with hard disks idle. These are manufacturer specifications, not measurements from this review, and installed drives or actual settings affect power and sound. The wider chassis is a practical space consideration next to the two-bay AS5402T.

Package checks and model comparisons

ASUSTOR’s AS5404T package page lists the NAS, quick installation guide, AC power cord and adapter, two Cat 5e LAN cables, sixteen flat-head screws for 2.5-inch HDDs, and a power-cord bracket. That tells you what the manufacturer describes as standard contents; a retailer may add drives or other items, so compare the exact seller listing and return terms. Do not infer an installed drive, a licensed app, or a configured RAID from product-page marketing.

Against the AS5402T, the four-bay AS5404T adds two native SATA positions while retaining the four-M.2 concept, 4 GB base memory, 16-GB memory ceiling, and dual 2.5-Gigabit links. If you need more than four native SATA bays, a different model class may fit better; if you will never use the M.2 layer, a simpler NAS may be a better match. The earlier NIMBUSTOR 4 (AS5304T) is another four-bay option in the reviewed library, but its documented hardware differs; the AS5404T’s four M.2 slots and N5105 profile should not be assigned to that earlier model.

What remains to verify before purchase

ASUSTOR’s current support-status table lists AS5404T as generally available and supported, with a three-year warranty entry. That is manufacturer status information, not proof of U.S. seller stock, an active offer, warranty transfer, seller coverage, or return policy. This review did not verify an exact U.S. retail suffix, seller-added bundle, price, or drive-and-firmware approval tuple.

Before choosing it, confirm the seller is offering the exact NIMBUSTOR 4 Gen2 (AS5404T), not the older AS5304T or another package. Check every proposed SATA and M.2 drive against the current model-specific compatibility information; decide how much of the four-bay layout a mirror should consume; and budget for a separate, restorable backup. Treat the two 2.5-Gigabit sockets as individual link ratings unless your full network is configured for a supported multi-link arrangement. These checks preserve the AS5404T’s real advantages—four native SATA bays, four separate M.2 slots, and two individual 2.5-Gigabit ports—without turning manufacturer feature claims into promises about your installation.