The Netac ZX20 is the company's new flagship portable SSD. It uses the Silicon Motion SM2320G controller, which combines the USB interface and SSD controller into a single IC. This helps reduce cost and complexity, as just one instead of two chips is required. Obviously, this also means that drives can be more compact, because components are more tightly integrated. Unlike many other vendors, which build external SSDs by including a full-sized M.2 NVMe inside the case, Netac was smart, choosing to go with a proper, highly compact design. As a result, you get a tiny portable high-performance SSD—nearly all other competitors are considerably bigger.

Performance numbers of the ZX20 are impressive. Thanks to its fast USB 3.2 Gen 2x2 20 Gbps interface, the 1 GB/s bottleneck of most external SSDs is no longer a problem. In terms of sequential speeds, the drive almost reaches 2 GB/s at even low queue depths, which is important if you copy just a single file at a time, the most common usage scenario for a portable SSD. Another important data point is that sequential mixed—write a file and read another file at the same time—completes at 1.2 GB/s, which is much faster than most other drives in our test group. Random IO is not that important for a portable SSD unless you want to run portable programs or games from it; for example, when using the SSD to expand storage on game consoles. In that use case, performance is still really good, but not by as big a margin as with sequential IO. The only weak spot of the ZX20 is random IO mixed, as there is no DRAM cache for the mapping tables of the SSD. However, that isn't a dealbreaker, as it is an ultra-rare workload for a portable SSD.

Physical construction of the Netac ZX20 is solid, and it looks good. Some competing portable drives offer a metal shell, which might help with durability, but will increase the price, too. Also, some metal surfaces are very susceptible to fingerprint residue—this is no issue with the ZX20. I do with they had some sort of IP dust/water protection rating, which shouldn't be that difficult to achieve, given the construction of the drive. Unlike some competing drives, you do not get an activity indicator LED, which can be useful to find out whether a transfer operation has completed. Temperatures were no problem on the ZX20—it gets slightly warm to touch.

Sustained write speeds of the Netac ZX20 aren't that impressive. With 270 MB/s to fill the whole disk, it's slower than many of its competitors. If you plan on copying hundreds of gigabytes per session without pause, then look elsewhere. If your working sets are smaller, up to 100 GB writes, or you have pauses in transfers that give the drive room to breathe, the ZX20 can shine though.

Finding the Netac ZX20 in stores isn't easy, but if you do, it should sell for around $120 USD, which is a very reasonable price point. On the other hand that's $30 more expensive than various USB 3.2 10 Gbps drives, which offer half the theoretical performance cap, but may still be fast enough in most scenarios. Out of the 20 Gbps drives, the strongest competitors are the WD Black and ADATA SE880 for $130 and the Kingston XS2000 for $110. The Lexar SL660 is fairly expensive at $150, but offers RGB lighting, just like the ADATA SE900G ($110). If you can't find the ZX20, then you might want to consider the Kingston XS2000 and ADATA SE880, which both are based on the same hardware components as the Netac ZX20 and come with a very compact form factor, too. If you need a lot of storage, then the ZX20 might be too small, because its capacity tops out at 1 TB, some competing drives go up to 4 TB, high capacity external SSDs are somewhat of a niche market though.

Overall the Netac ZX20 is a fantastic USB 3.2 2x2 20 Gbps SSD, not coming cheap, but offering a ton of performance. To enjoy the blazing speeds of the drive, your computer has to support the USB 3.2 Gen 2x2 20 Gbps interface, or the SSD will operate at 10 Gbps, or even less. For AMD AM4, only six motherboards exist with 20 Gbps USB, so you'll probably have to use a PCIe add-in card. For Intel, the selection is decent, but requires the LGA1200/1700 platform. There's a reason that AM5 motherboards are so expensive—they are feature-packed—a majority of them support the USB 3.2 2x2 20 Gbps interface. You can also pair these super-fast USB SSDs with the new consoles, but neither PS5 nor Xbox Series X have support for 20 Gbps USB, so your gains will be limited.