TerraMaster's 10Gbps D1 SSD enclosure provides solid speeds up to 10Gbps in a durable, heat-dissipating build that's resistant to environmental elements under typical conditions. Interestingly, it appeared as an internal NVMe drive when connected to a Thunderbolt 5 interface, leading to 40Gbps read speeds, 20Gbps writes, and various system complications.

This marks the third entry in our examination of TerraMaster's tough, aluminum-based external SSD housings, building on earlier evaluations of the 80Gbps D1 SSD Pro and 40Gbps D1 SSD Plus models. The D1 SSD stands out for its more compact size and inclusion of an IP67 certification, while delivering reliable 10Gbps capabilities in most scenarios.

Surprisingly, tests on our Thunderbolt 5 connection revealed reads exceeding 4GB/s and writes around 2GB/s. Unfortunately, this unexpected speed boost came with multiple system glitches, making it unwise to replicate the setup.

For a detailed breakdown of these performance quirks, check the benchmarks section, which explores this unusual occurrence we hadn't anticipated.

Continue reading for in-depth details, followed by our guide to top external storage options.

Similar to its predecessors, the D1 SSD features an aluminum body with cooling fins. What sets it apart is the rubber seal around the internals, designed to block out dust and water, as visible in the accompanying photo.

Measuring about 4.5 inches in length, 1.75 inches across, and 0.75 inches high, the loaded unit weighs roughly 5.5 ounces. TerraMaster includes a premium zippered protective case, a Type-C cable, and a screwdriver for SSD installation.

One design drawback is the somewhat tricky process of securing the enclosure's two parts together. The top piece has tabs that must align precisely with slots on the base, requiring careful positioning to achieve a smooth fit.

Once properly aligned, the ends align evenly, and the built-in screw tightens without resistance. Misalignment prevents this.

Priced at just $40, this IP67-rated, aluminum enclosure excels in staying cool despite its compact form. Users must supply their own NVMe SSD, with any PCIe 3.0 or higher model sufficient since they surpass USB 10Gbps limits. Testing involved PCIe 4.0 and 5.0 drives, which enabled the observed results.

Prior to discussing standard 10Gbps benchmarks (which were strong – feel free to jump ahead if that's your focus), let's address a rare phenomenon unfamiliar to us.

This quirk only surfaced after initial connection to a Thunderbolt 5 port using a compatible cable. Subsequently, the 10Gbps D1 SSD achieved 4GB/s reads akin to a 40Gbps device and 2GB/s writes like a 20Gbps one. Remarkably, this persisted even on a USB 3.2 Gen 2x2 port limited to 20Gbps.

Investigating revealed that Windows initially detected the D1 SSD as an internal NVMe drive. Drive properties confirmed use of the stornvme driver instead of the usual UASPStor, allowing direct PCIe tunneling over USB in this case – at least on our setup (detailed later).

The image illustrates recognition of the internal SSD rather than the enclosure.

While the speeds impressed, problems emerged. On an M4 Max Mac Studio, it appeared as a 1TB Orico unit in Disk Utility but vanished from Finder. Possibly due to prior use of the 2TB T-Force SSD in an Orico case, or some partnership? Unclear.

Switching to a 2TB Solidigm PCIe 4.0 SSD resolved the Mac issue, but back on Windows, Disk Management detected two uninitialized drives, one being our Linux Mint partition. The cause likely tied to hot-unplugging an emulated internal NVMe, which isn't standard.

With the Solidigm SSD, Windows tests again hit about 4GB/s reads and 2GB/s writes. On macOS and Linux, speeds settled at 1GB/s, consistent with 10Gbps USB.

Reformatting via Diskpart, reinitializing, partitioning, and rebooting on the USB 3.2 Gen 2x2 port properly identified it as an external USB device.

This isn't the first oddity with TerraMaster's software; the D1 SSD Pro required a firmware patch to reach 80Gbps writes with its included cable. Other enclosures using the same Realtek RTL921 PCIe 4.0 bridge chip in the D1 SSD haven't shown similar anomalies.

The graphs depict standard 10Gbps results alongside NVMe-emulated figures (in light blue). Overall, the D1 SSD matches top performers in 10Gbps tests.

CrystalDiskMark 8's 4K read scores also stand out for 10Gbps enclosures.

In 48GB transfers, the D1 SSD outperformed some competitors while trailing others at 10Gbps. Under NVMe emulation, results were exceptionally high.

Further NVMe-like excellence appeared in 450GB write tests, surpassing the Seagate Ultra Compact SSD and Adata SC735 at genuine 10Gbps. FastCopy had minimal impact on extended writes.

As a standard 10Gbps drive, the D1 SSD delivers strong results. Yet the NVMe emulation sparks curiosity: How does it work, and why isn't this more common in enclosures?

With its stylish appearance, efficient cooling, weather resistance, and budget-friendly price, the D1 SSD shines in build quality. Expect TerraMaster to patch the NVMe glitch via firmware, and avoid risking system disruptions. Still, witnessing 40Gbps reads from a 10Gbps USB SSD was thrilling.

To replicate – potentially linked to my knack for uncovering glitches (a mixed gift) – never disconnect while powered. I disclaim any issues from non-standard use as a regular 10Gbps USB SSD.

Testing occurs on Windows 11 24H2 (64-bit) booted from a PCIe 4.0 Samsung 990 Pro SSD in an Asus Z890-Creator WiFi motherboard (supporting PCIe 4.0/5.0). Powered by a Core Ultra i5 225 CPU and 128GB (2x64GB Crucial DDR5 5600MHz) RAM.

Integrated 20Gbps USB and Thunderbolt 5 come via motherboard and Intel CPU/GPU. Test PCIe 5.0 SSDs sit in an Asus Hyper M.2 x16 Gen5 card in a PCIe 5.0 slot.

Benchmarks include CrystalDiskMark 8.0.4 (and 9), AS SSD 2, and ATTO 4 (only the first reported here) for peak potential. Real-world tests feature 48GB transfers and 450GB writes via Windows Explorer, plus admin-run FastCopy for optimized speeds.

The counterpart drive is a 25GB/s RAID 0 of two SSDs on the Asus Hyper M.2 x16 Gen5 (previously a RAM disk for 48GB). All on freshly TRIMmed NTFS volumes for best results. Note: Real usage may slow as drives fill, though modern SSDs with advanced controllers and NAND mitigate this.

Jon Jacobi, a musician and former x86/6800 programmer with decades of computing passion, covers TVs, SSDs, dash cams, remote software, Bluetooth audio, and various tech gear.