UGREEN40Gbps M.2 NVMe Enclosure with Cooling Fan, Anti-Drop SSD Enclosure for MacBook, Aluminum M.2 Enclosure Support M/B+M Key Size 2280/2260/2242/2230 Compatible with Thunderbolt 3/4/USB4/3.2/3.1

I started off with the Acasis Thunderbolt 4 enclosure. I can confirm that the Acasis unit does indeed have a Thunderbolt 4 compatible board, and the UGreen does not. However, my testing didn't show a huge difference in speeds, at least not enough to justify the trade off in thermals.The Acasis unit got VERY hot. The included thermal pad is not thick enough to reach the top aluminum plate, and I assume they do this as the Acasis seems to be geared more towards swapping NVME's regularly, vs the UGreen which seems to be geared toward installing once, and that NVME living in the enclosure long term (tools vs tool-less).The operational temp for most NVME SSD's is technically 30*C-72*C (86*F-161*F). In the Acasis, even at idle, I would clock the enclosure up at 120*F, and the drive with the top plate removed at 123*F. Under a blackmagic stress test, I could easily get the drive up to 155*F and enclosure up to 162*F.While that is within the margin of safety, and the enclosure is obviously dissipating heat as it was hotter than the drive itself, that was just too close to max temps for my comfort and I really think long term that the drive would not live very long.Now on to the UGreen. The design is MUCH better. The fan does do something. It doesn't pass air over the SSD itself, it moves air from under the SSD and over the enclosures main board. The big difference is the UGreen has a solid copper to plate, and the included thermal pad is thick enough that on a standard NVME drive it brings the height up to the height of the rest of the enclosure (you can see it in photo 2) and the NVME makes DIRECT contact with the copper plate.The temperature readings I took were after running blackmagic 5GB stress test for 10 minutes straight. The second photo at 92.3F is of the lower end of the NVME, the 108*F is the upper end. The memory modules themselves were in the 92-95*F area, well within my comfort zone.Overall, I'm much more happy with this unit over the Acasis. I think the Acasis could work if you went and got a thicker thermal pad, but I love the aesthetics of the UGreen, and in my use case, this is a drive that will always live in the enclosure, so having a screw to keep it installed is actually a pro for me. I skipped the included rubber wrap as NVME's aren't going to be damaged by shock or vibration, and I don't care if the enclosure anodizing gets scratched.Blackmagic test results done on a Macbook with thunderbolt 4 capabilities, although it is falling back to USB 3.4 due to the controller in the UGreen not supporting Thunderbolt 4. Still plenty fast for me, and way faster than any off the shelf external SSD offering.

This little enclosure is really great, probably the best on the market right now. See below a quick summary of Pros and Cons:Pros:- Small. Although I bought it to have it on my desk, I could easily travel with it.- Rock solid performance (see attached image). Best of all, **performance is maintained even when using longer cables**. That is not always the case with other enclosures (e.g. Satechi). I ran tests using the included cable and a 3.3-ft thunderbolt 4 compatible cable. Transfer numbers were basically the same.- Built like a tank. It feels like a solid block of aluminum, even the internals are metallic.- It is provided with an extremely silent fan. It is temperature controlled, so it only kicks in when needed.- Includes a removable silicone sleeve.- Adequate price.Cons:- Included cable, although it works, it's a bit short and feels somewhat cheap. A braided one would've been great.- Since closing the lid requires a short sliding motion, the friction against the thermal pad makes it a bit hard to close. This is really a minor thing.I didn't know Ugreen made this type of devices. I'll keep them in mind next time I'm on the market for a similar product.

I've been looking for a nice USB4 enclosure. This one fit the bill. It looks fantastic, feels like I could drop it from an airplane and it would leave a crater; it's that well made.It works on both my Mac Studio M2 Max via Thunderbolt 3 and on my PC using USB4. Its even compatible with my XBox Series X and Playstation 5.Installing the drive required no instructions or effort and once assembled, it's read immediately upon plugging it in.Unfortunately, as nice as this enclosure is, it's not touching the speed of any PCIe Gen 4 NVMe drive. It works perfect with a PCIe Gen 3 drive and will come close to maxing it out, but it treats a Gen 4 drive as if it were Gen 3. This makes it kind of pointless, especially given the cost. While I don't entirely feel cheated, there is definitely a lot of room for improvement in the USB4 controller in this unit. It does work quite a bit better on the Mac Studio M2 Max, so I'm satisfied. It's nearly twice the speed on the Mac than any USB4 device.Considering a rugged enclosure of this quality for USB 3.2 is close to the same price, it's not expensive enough to send it back.I'd definitely consider another brand if you really need a USB4 enclosure. If you're looking for a really good Thunderbolt 3 drive, this is great considering it keeps the drive nice and cool.If you're looking for a great Thunderbolt 3 enclosure, buy this, I highly recommend this. However, if you're looking to use this with a USB4 device, I'd take a chance on another. Bear in mind, this is not the first drive enclosure I've seen underperform with USB4, so maybe there's hope for better support on devices with USB4 ports.

I’m quite impressed. The materials are top-notch, and it feels incredibly premium in your hand—definitely not one of those flimsy enclosures you’d worry about breaking after a few uses. For day-to-day usage, it works flawlessly.That said, I did encounter a downside: the cooling performance. If you’re transferring large amounts of data in one go, the enclosure struggles to dissipate the heat generated by the SSD. While this is likely an edge-case scenario for most users, it’s worth noting if your workflow involves heavy read/write operations.For regular use, this enclosure is a fantastic choice. But if you frequently deal with large data transfers, you might want to explore other options with better cooling capabilities.