Tom's Hardware posted a review on the Samsung 1TB Portable SSD X5
A quote from the article:
Samsung's 1TB Portable SSD X5 brings the speed of the Thunderbolt 3 interface and the NVMe protocol to a speedy external SSD. Leading edge technology almost always comes at a premium, and the latest storage products are no exception. Samsung's attractive Portable SSD X5 builds on the company's reputation for creating some of the fastest and classiest SSD storage solutions on the market, but it is pricey: The Portable SSD X5 is easily three times more expensive per gigabyte than most portable USB SSDs.Samsung 1TB Portable SSD X5 Review
The Portable X5 does bring a lot to the table, though. Samsung says the drive has supercar design influences and the performance to match. Samsung’s Portable SSD X5 is the company's first NVMe-based portable SSD with the Thunderbolt 3 interface. The interface enables high-end performance that stretches up to a blistering 2.8/2.3 GB/s of read/write throughput.