The Ugreen CM642 offers a compelling way to transform any NVMe SSD into a high-speed external drive. This 40Gbps USB4 enclosure delivers impressive performance at a surprisingly affordable price, making it an excellent choice for users seeking a customizable and portable storage solution.
Introduction
External SSDs are becoming increasingly popular for their speed and portability. The Ugreen CM642 distinguishes itself by allowing users to select their preferred NVMe SSD, offering flexibility in capacity and performance. This review examines the CM642’s features, performance, and overall value.
Features and Design
The Ugreen CM642 boasts a sleek, gun-metal gray design with copper accents. The enclosure is robustly constructed, primarily from metal, giving it a premium feel. Measuring approximately 4.5 inches long, 1.75 inches wide, and 0.75 inches thick, it’s compact enough for easy portability. A single, non-captive screw secures the internal M.2 NVMe slot, compatible with 2230, 2242, 2260, and 2280 form factors. Ugreen thoughtfully includes a small screwdriver, along with Type-A to Type-C and Type-C to Type-C cables. Crucially, using these included cables is essential for achieving the full 40Gbps performance. An included silicone sleeve provides additional protection against scratches and prevents slippage.
Internal view of the Ugreen CM642
The CM642 utilizes the ASMedia ASM2464PD USB4 chip, contributing to its impressive speeds. A small, quiet fan effectively manages heat dissipation, ensuring optimal performance during sustained operation.
Ugreen CM642 with silicone sleeve
Pricing and Value
Priced at $110, the CM642 offers exceptional value, particularly considering its 40Gbps performance. While less expensive USB 3.2 Gen 2×2 enclosures exist, they are limited to 20Gbps (approximately 2GBps) and may drop to 10Gbps on Mac Thunderbolt ports. The CM642, being USB4 compliant, maintains its full speed on both Windows and Mac systems.
The cost of adding an NVMe SSD ranges from approximately $40 for a 256GB model to $650 for an 8TB drive. The sweet spot for capacity and price lies between 1TB ($60) and 2TB ($160). Choosing a PCIe 5.0 or even PCIe 4.0 SSD offers no significant advantage with the CM642, as USB4 cannot fully utilize their bandwidth. Standard NVMe M.2 SSD buying advice still applies: avoid QLC NAND for write-intensive workloads, opt for a DRAM-equipped SSD for running operating systems or demanding random performance, and consider TLC HMB designs for other use cases.
Performance
The Ugreen CM642 sets a new standard for unpopulated USB4 enclosures, boasting the fastest speeds we’ve tested. When paired with a high-performance NVMe SSD like the WD SN850X 8TB, the CM642 surpasses even pre-populated USB4 SSDs in benchmark tests.
CrystalDiskMark 8 sequential read/write results
CrystalDiskMark 8 results show excellent sequential and random 4K performance. The inclusion of high-quality 40Gbps cables is vital for achieving these speeds; using older cables results in significantly reduced performance.
CrystalDiskMark 8 random 4K results
Real-world 48GB and 450GB transfer tests further solidify the CM642’s impressive performance, demonstrating its capability for handling large file transfers efficiently.
48GB transfer test results
450GB transfer test results
The CM642 effectively manages thermal performance, avoiding any throttling issues during intensive tasks.
Conclusion
The Ugreen CM642 provides an exceptional combination of performance, flexibility, and value. Whether you have a spare NVMe SSD or plan to purchase a new one, the CM642 offers a compelling solution for building a high-speed external drive. Its robust design, excellent performance, and affordable price make it a top contender in the USB4 enclosure market.
