The TerraMaster D8 Hybrid is a unique product in the market in that it allows both hard drives and M.2 NVMe SSDs to be installed in an external enclosure, but it doesn't come without caveats. For someone looking for a simple to use, external backup solution, the D8 Hybrid might fit the bill, especially when set to RAID 1 mode, as this makes sure you always have an extra copy of the data you're backing up. Another plus is that you can copy data to the RAID drives and the two individual mechanical drives simultaneously, without losing performance. It can also be handy to use for storing data that doesn't need to be on your system drives at all times, but this is when we start running into the limitations of the hardware. The drawback of only being able to use two drives in RAID mode might also put some potential customers off, and it's a bit of a strange design choice by TerraMaster.

As nice as it is to be able to stick M.2 NVMe drives into the D8 Hybrid, especially if you have some spare drives from older systems or an upgrade, the 10 Gbps USB 3.2 Gen 2 interface is really a limiting factor here. We would like to have seen at least a 20 Gbps USB 3.2 Gen 2x2 interface—or even better—USB4 at this point in time, as it would make the NVMe slots a lot more useful. As it stands, the D8 Hybrid ends up being useful for accessing data on M.2 NVMe drives from old systems, but you wouldn't really want to use it as a fast external storage device, since it's limited by the USB interface. There are also limitations within Windows that prevent the drives inside the D8 Hybrid from being used in software RAID, which is a real shame.

With that said, we shouldn't forget that the D8 Hybrid can also be used to expand TerraMaster's range of NAS appliances and add more storage to them. In this scenario the D8 Hybrid is most likely a lot more useful, but as we didn't have a TerraMaster NAS at hand to test this with, we don't know how well it works. However, the company claims that it's possible to add the drives inside the D8 Hybrid to "storage pools and various RAID modes," which makes it just like any other NAS expansion unit.

At the crowdfunding price point, the D8 Hybrid could be a good alternative for those that find a NAS too complicated or too costly, but at the MSRP, it's getting very close to entry-level NAS pricing, which makes it less of an attractive option. That said, the 10 Gbps USB 3.2 Gen 2 interface will offer better performance than most low-cost NAS appliances that only have 1 Gbps Ethernet ports. As such, if speedy access to data is important to you, then this DAS might be what you've been looking for, as long as said data doesn't need to be easily shared between multiple client devices. This is an obvious limitation of a DAS, but there's nothing quite like the D8 Hybrid on the market, although TerraMaster also offers the D5 Hybrid which supports two hard drives and three NVMe SSDs for those that don't need as much storage space.

We were also disappointed to find freeware software provided as the backup software from TerraMaster. This feels cheap and the nag screens about upgrading to the pro version doesn't help either. The TPC Backupper does, however, seem to work as intended, and it's easy enough to use, but if you're going to provide software, don't make it look like you're providing something extra, when it's freely available in the first place.

At the US$200 crowdfunding price point, the TerraMaster D8 Hybrid could be a good deal for those that are looking for a simple backup and storage solution, but it's important to consider the limitations of the hardware and make sure it'll suit your needs.