Ugreen CM850 USB4 Enclosure: Fast 40Gbps with any NVMe SSD

3GBps transfers for far less than Thunderbolt.

- BY JON JACOBI

If you’ve shopped Thunderbolt in your quest for fast external Mac storage, you’ll know that sticker shock is often a pitfall of the process. You can reduce the monetary jolt by switching your search to USB4, which, being an outgrowth of Intel’s PCIe over-a-wire technology, is just as fast as Thunderbolt 4.

And it’s significantly cheaper than Thunderbolt, especially if you roll your own with something such as the UGreen CM850 NVMe M.2 enclosure.

The CM850 is a more affordable version of the Ugreen’s CM642 that uses the same ASMedia ASM2464PD chip. It’s a gunmetal-gray aluminum enclosure that’s approximately 4.75x2.1x0.6 inches and weighs 4.4 ounces.

Its heft is nice, as is the top panel that pops off to reveal the internal M.2/NVMe slot supporting 2230 (22mm wide, 30mm long) to 2280 SSDs secured by a captive screw. The panel doesn't have small screws to deal with.

Your options on the Mac for 20Gbps/40Gbps performance are Thunderbolt 3, 4, or 5, all of which involve significantly pricier enclosures and are not supported on the majority of Windows machines. That can be important if you work in a mixed environment.