In testing the real-world Thunderbolt performance of the Envoy Pro SX, I copied a 10.5 GB file from my computer to the external SSD in 7.2 seconds. Transferring the same file from the OWC product to my computer took 10 seconds. These scores were in line with our expectations, and running them repeatedly revealed a variance of around 50Mb/s between the best and the worst in each test. The competition

The Envoy Pro EX line of external storage drives are at the top end of the external SSD spectrum in almost every way, including design, ruggedness, and build quality. And their price tags reflect that. It should be noted that if you only have a 5Gbit USB port as per the original USB 3.0 or USB 3.2 Gen 1 as it has been relabelled, then read and write speed will be below SATA SSDs, at around 450MB/s. Those wanting faster external drives can use one designed for USB 3.2 Gen 2x2 or Thunderbolt, and OWC makes plenty of the latter. But, it’s also worth saying that a modern system with Thunderbolt 3 ports and a powerful CPU is essential if you want to get the best write speeds from this device.

It’s also certified dustproof, drop-proof, and waterproof, and comes bundled with a cord that supports both Type-C and Type-A ports. The accessory comes with the necessary Thunderbolt cable. This is 25 inches long — plenty enough to be useful. OWC Envoy Pro SX performance The bottom of the drive has two non-skid rubber feet to prevent it from sliding around on a desk or other surface. On the front of the drive is a slim LED status light that appears blue when the drive is powered on and flashes slowly during file transfers, but the LED isn't very bright, so I found it pretty useless during daylight hours. (I'm no pro photographer, so the picture above makes the LED look brighter than it is.) The Sabrent option doesn’t have the same IP67 rating as the Envoy Pro FX and is exclusively for Thunderbolt ports, but the performance levels are comparable for significantly less money.

As an external drive that fits in the palm of my hand, the Envoy Pro FX can easily be brought on the go, making it a convenient, portable solution for storing files while traveling. With a single Thunderbolt 3 cable that connects to a Mac for data and power, IP67-rated water and dust resistance, and military-grade drop protection, the Envoy Pro FX provides a plug-and-play experience without any worry. How often your equipment gets wet might bend purchasing decisions in its direction, but not all users will consider it a deal-breaking requirement. But this isn’t the only caveat, as external speeds are dependent on the internal drive performance of the computer it is connected.Flexible Compatibility: Plug & play with past, present and future Macs, Windows and Linux PCs, iPad Pros, Chromebooks, and Surface devices While the OWC is technically not the fastest USB Type-C drive we've ever tested, the differences in speed among all of these USB 3.2 Gen 2, PCI Express-based models are so minimal that you'd really need to be looming over the drives with a stopwatch to detect them. And even then, you might not. A Great Choice at the Top End With a sleek aluminum housing, the Envoy Pro FX resembles an Apple product, but the white OWC logo and Envoy Pro FX branding takes away from the aesthetic. The drive's "charcoal gray" color is a bit darker than the Space Gray finish of the MacBook Pro, but they still look nice side by side. Along the left and right sides of the drive are what OWC calls "deeply grooved fins" to help with heat dissipation and ensure sustained performance. The fanless drive never felt overly hot to the touch during some large file transfers in my testing.

The OWC Envoy Pro SX can handle both. At up to 2847MBps, it’s about as fast as an external SSD can be. And it’s rugged so you don’t have to baby it. Hardware and design OWC has published a collection of benchmarks that outline the speeds that can be achieved with optimal configurations. Using a MacBook Pro 16 M1, the best speed achieved was 2,044 MB/s write 2506 MB reads on the 2TB capacity drive.

OWC Envoy Pro SX review

The Elektron's sequential read and write scores as measured by Crystal DiskMark are a hair short of its rated speeds and typical of USB 3.2 Gen 2 external drives, which generally fall in a narrow range around 1,000MBps for both read and write. The SanDisk Extreme Portable SSD V2 had the highest read and write scores in this test, but the difference between its and the OWC's scores is minimal compared with that between any USB 3.2 Gen 2 drive and any SATA drive—with read and write scores around 500MBps or less—or any USB 3.2 Gen 2x2 drive, with scores pushing 2,000MBps for both read and write. A glance at our Crystal DiskMark chart should be all you need to figure out which bus each drive is using. In fact, the only anomaly among the USB 3.2 Gen 2 drives in our test group was the unusually low write score turned in by the ADATA SE800. (Fortunately, it had a saving grace, the extreme durability and ruggedness that helped earn it Editors' Choice honors.)

Overall, the OWC Envoy Pro Elektron is a gorgeous piece of equipment that most would love to own, but not all could afford this level of quality.

Thunderbolt 2 and Thunderbolt 3 have physically different connectors with the former being physically compatible with the mini-DisplayPort format. TB3 doubles the bandwidth to 40Gbps, halves the power consumption, and can deliver up to 100W of power to other devices. Like Firewire and USB, it has been developed as an open standard driven by Intel. Sequential read/write (max) performance based on testing an OWC Aura Pro III equipped Envoy Pro Elektron connected to an iMac Pro Late 2017 (iMacPro1,1) with 32GB RAM and 3.2GHz processor running AJA System Test (4K-Full resolution, 64GB file size, 10bit RGB codec, single file test) and Diglloyd DiskTester (fill-volume test). The drive comes preloaded with OWC's Drive Guide formatting utility for configuring the drive, with options to create a single Apple File System (APFS) volume that fills the entire drive for macOS High Sierra and later, a single HFS+ volume that fills the entire drive for older macOS versions, or a single exFAT volume that fills the entire drive for use with both macOS and Windows. The drive can also be configured manually.