ASUSTOR Nimbustor 2 Gen2 AS5402T review: This 2.5GbE NAS is a terrific Plex server

ASUSTOR is looking to reinvent its NAS portfolio with the Nimbustor 2 Gen2 AS5402T, and the 2-bay NAS gets a lot right. It uses Intel's proven hardware platform, has four M.2 slots — more than any other NAS in this segment — and comes with 2.5 Gigabit Ethernet connectivity.

The biggest issue with ASUSTOR servers in the past was the software, and the brand was the target of a ransomware attack two years ago. So it overhauled the software, beefed up its security measures, and rolled out a ton of new useful features.

ASUSTOR is betting on value to get potential customers to pick up the AS5402T over other products in this segment, and this is the best hardware package of any 2-bay NAS in the sub-$500 category. I used the AS5402T for just over three months, and here's why I think it has a lot of potential.

ASUSTOR AS5402T: Pricing and specs

ASUSTOR unveiled the AS5402T alongside the 4-bay AS5404T back in May 2023, and the NAS is now available globally. The AS5402T retails for $369 on Amazon in the U.S., and it is available from all major retailers. Over in the U.K., the NAS costs £374 ($473). ASUSTOR offers a three-year warranty as standard with the NAS. Calling a product Nimbustor 2 Gen2 AS5402T gets annoying really quickly, so I'm just going to refer to it as the AS5402T in the rest of the review.

ASUSTOR AS5402T: Design

NAS manufacturers don't usually change the design of their products, and that is the case with the AS5402T as well. It has the same design language as ASUSTOR's earlier offerings, and the unassuming design means it easily blends into the background. You don't get any vents on the sides, but there is a 70mm fan at the back that does a good job ensuring the drives don't get too hot.

That said, ASUSTOR went with a geometric pattern throughout that looks quite good, and it gives the NAS a little bit of character. The NAS has two drive bays, and they easily slide out. There is a shroud covering the drive bays, and it attaches magnetically to the enclosure. While the rest of the AS5402T has a plastic design with a matte texture that doesn't pick up dust easily, the shroud is made out of glossy plastic, and it is a dust magnet.

There are status LEDs for the hard drives, network ports, and USB ports, and you get a USB-A port on the left. Installation of 3.5-inch HDDs is tool-free, but you'll need to use screws if you're mounting 2.5-inch SSDs or HDDs. One of the best features of the AS5402T is that it has four M.2 2280 slots. The downside is that accessing these slots isn't easy; you'll need to remove the screws at the back of the enclosure, take out the hard drive bays, and then slide the front cover back.

This lets you access the innards of the chassis, with the M.2 slots located at the top. Installing the SSDs is easy enough once you get to the slots, but a slide-out panel would have made things considerably easier. There are vents above the M.2 slots that offer some amount of passive cooling, but I would have liked to see thermal pads installed underneath each slot. And considering a screwdriver is necessary to get to the M.2 slots, ASUSTOR should have included one in the box — like TerraMaster.

Other than that drawback, I didn't notice any issues with the design. ASUSTOR did a good job maintaining design consistency with previous generations, and the fan at the back manages thermals well without getting too loud.

ASUSTOR AS5402T: Ports

ASUSTOR is known for delivering a good value with its NAS servers, and the AS5402T is no different. The NAS has two 2.5 Gigabit Ethernet ports at the back, and you get dual USB-A ports as well. What I particularly like is the inclusion of an HDMI 2.0 port; this allows the NAS to be connected to a TV.

All three USB-A ports now use the USB 3.2 Gen 2 standard, and they get the full 10Gbps bandwidth, so if you're looking to connect external drives to the NAS, you'll get fast transfers. The big differentiator is the quad M.2 slots on the NAS, so if you're looking to mix traditional HDDs with fast SSD storage, you can do that with the AS5402T.

Interestingly, the AS5402T reuses the same M.2 backplane as the costlier AS6707T, and the HDD backplane is the same as the AS5302T. This doesn't affect the usability of the NAS in any way, and there are lots of other brands that use the same hardware across their products. But given how ASUSTOR labels its model number on all the parts, it's straightforward to see what servers they were designed for. 

ASUSTOR AS5402T: Software

ASUSTOR was the target of a ransomware attack two years ago, and following the incident, the brand overhauled its security measures. The ASUSTOR Data Master (ADM) web-based interface suggests ways to tighten the security of the NAS after you log in, and it picked up a visual refresh — it now has a distinct gaming aesthetic, and the bold styling looks good.

The interface still doesn't look quite as polished as what you get with DSM, but ASUSTOR did a good job adding a lot of features. Icon management is a little intuitive, and settings could have been organized better, but on the whole, you get a ton of useful utilities, including the likes of Home Assistant, Tailscale, Plex, AdGuard, and more.

ASUSTOR also has a suite of mobile apps that let you back up photos and videos, and while they do a decent job, they are in need of an overhaul.

ASUSTOR AS5402T: Performance

ASUSTOR is continuing to offer Intel hardware on its NAS enclosures, and the AS5402T is powered by the quad-core Celeron N5105, delivering sizeable gains over the N4xxx series. It is plenty fast in daily use, and it an outstanding choice if you want to set up a powerful Plex server.

The AS5402T does a great job with hardware transcoding in general, and if you're looking to use the feature in Plex, this is one of the best home NAS servers available. It is better than the DiskStation DS224+ — my current 2-bay pick — when it comes to Plex streaming, and it holds up particularly well with high bitrate content.

The AS5402T has 4GB of DDR4 RAM out of the box, and there's another SO-DIMM slot available that lets you add up to an 8GB module. ASUSTOR doesn't hobble the NAS in any way, so the best NAS hard drives will work without any issues on the AS5402T, including the IronWolf Pro and WD's Red Pro series. You can even slot in the new 24TB IronWolf Pro drives in the NAS, but seeing as how they cost $549 at the moment, you're better off buying 8TB IronWolf HDDs.

I tested the AS5402T with dual 6TB IronWolf drives, and it was easy enough to saturate the transfer rate of the hard drives when moving data from the SSD of a Windows machine. The fact that you get 2.5GbE connectivity makes things significantly easier, and you don't need to worry about the network ports being the limitation in this area.

ASUSTOR AS5402T: The competition

If you like the look of the AS5402T but want something with more drive bays, you should consider the Nimbustor 4 Gen2 AS5404T. It has the same Celeron N5105 hardware, same number of ports at the back, and identical memory and M.2 slots. The only difference is that you get the ability to slot in four 3.5-inch drives, and outside of that, it is the same as the AS5402T.

The DiskStation DS224+ is more affordable, but you don't get anywhere close to the same level of hardware. You don't get any M.2 slots, you're limited to Gigabit Ethernet, and there's no hardware transcoding. The software features are the reason why the DS224+ is a big deal, but it doesn't measure up to the AS5402T in terms of the hardware.

ASUSTOR AS5402T: Should you buy it?

You should buy this if:

• You want a powerful Plex home server
• You need plenty of M.2 slots
• You want great hardware and multi-Gigabit connectivity

You shouldn't buy this if:

• You need polished software

On the whole, the AS5402T is one of the best home NAS servers you can get in this segment. The NAS has terrific hardware across the board, and it's clear that ASUSTOR is positioning it as a creator-focused model. The combination of M.2 slots and dual 2.5GbE connectivity makes it a great choice if you want to use SSD storage in addition to mechanical drives.

While ASUSTOR's software still needs a bit of work, the brand made a lot of positive moves in this area over the last 12 months. If you're looking to set up a powerful Plex server and want the best hardware, the AS5402T is an easy recommendation.