When it comes to performance, there's really nothing lacking when it comes to the TerraMaster F4-424 Max, as it's the fastest NAS we've tested to date, but it comes at the rather hefty price point of US$900. For that asking price, we would really like to have seen that TerraMaster had solved the issue with not being able to add normal heatsinks on the M.2 SSDs, especially considering TOS 6 is warning that the SSDs can get hot and that a heatsink should be used. Since no heatsinks were provided and even the 6 mm tall heatsinks that came bundled with the F8 SSD Plus didn't fit—as they wouldn't allow us to put the side of the housing back on—suitably tall heatsinks should be shipped with the F4-424 Max. This is obviously an issue with reusing the same basic housing for multiple devices, but at this price point, TerraMaster needs to have a rethink.

That aside, there are a lot of good things on offer here ranging from a fast processor to easily expandable DDR5 RAM, dual 10 Gbps Ethernet ports—which may be a bit overkill even here—plus all three USB ports are 10 Gbps USB 3.2 Gen 2 ports. The HDMI port still doesn't serve much of a purpose, but that's really a minor gripe, since we have a feeling most people don't put their NAS next to their TV and use it as a media player, but we could be wrong here. Hopefully TerraMaster will come up with a more functional housing for its next generation of hardware—one that not only solves the issue above, but adds somewhat more sophisticated drive trays as well—at least on a premium model like this. In general however, the hardware is solid.

This brings us to the software, where we had a couple of weird glitches. TOS 6 is still a solid upgrade over TOS 5.1 and TerraMaster is actively updating the OS, which is a good sign that known issues, security or otherwise, should eventually get patched. Unlike some of its competitors, TerraMaster doesn't offer a roadmap or even a broad overview in terms of what to expect next when it comes to new features, which is something that would be useful for potential customers missing features today, who may choose to go with a competing product instead. TerraMaster is still far behind the likes of QNAP and Synology on the OS side, but not everyone needs every feature possible, some just want a storage box to put it bluntly, and TerraMaster delivers here, as we've seen from the performance tests.

The F4-424 Max is a good piece of kit if you can afford the initial outlay. If four drive bays aren't enough for your needs, there's also the six-bay F6-424 Max for another US$100. This is clearly a product targeting more advanced users, or businesses that have the right network infrastructure to take advantage of a NAS with 10 Gbps Ethernet or wanting to use the load balancing options with it plugged into a managed switch. For those that don't need or won't splurge on all the features on offer here, TerraMaster offers the F4-424 Pro—which comes in two SKUs with either 16 or 32 GB of RAM as standard, making us wonder why TerraMaster decided to only offer an 8 GB SKU of the F4-424 Max—and of course the base F4-424. All the lower-end models are limited to 2.5 Gbps Ethernet and sport lower-end processors, but still offer good enough compute power for their intended use and obviously are at a significantly reduced price point. For those that want the more powerful hardware though, the F4-424 Max is hard to beat at US$900—nothing in the US$800-$1100 price range comes close in terms of features—which makes this a recommended NAS, despite a few niggles.