External bus-powered storage devices have grown both in storage capacity as well as speeds over the last decade. Thanks to rapid advancements in flash technology (including the advent of 3D NAND and NVMe) as well as faster host interfaces (such as Thunderbolt 3 and USB 3.x), we now have palm-sized flash-based storage devices capable of delivering 2GBps+ speeds. While those speeds can be achieved with Thunderbolt 3, mass-market devices have to rely on USB. Read on for a detailed review of the various high-speed external SSDs targeting the mainstream market.


High-performance external storage devices use either Thunderbolt 3 or USB 3.2 Gen 2 for the host interface. Traditional SATA SSDs (saturating at 560 MBps) can hardly take full advantage of thebandwidth offered by USB 3.2 Gen 2. Last year, we took a look at a couple of NVMe to USB 3.2 Gen 2 enclosures from MyDigitalSSD and Plugable. Since then, we have had various leading vendors come out with their own solutions for this market segment. A steady stream of USB 3.2 Gen 2 external SSDs have been coming in to our lab over the last six months, with SanDisk's Extreme Pro Portable SSD and Samsung's Portable SSD T7 Touch (announced at CES) being the latest.

UL / Futuremark also updated their PCMark 10 benchmark with a storage bench recently. Our usual synthetic benchmarks - CrystalDiskMark and ATTO - have also had newer versions released since we last updated our benchmark suite for direct-attached storage devices in 2017. Over the winter holidays, we tweaked our evaluation suite and processed all the USB 3.2 Gen 2 SSDs that had come in over the preceding months through it.

The list of DAS units being reviewed today is provided below.

  • Samsung Portable SSD T7 Touch 1TB
  • SanDisk Extreme Pro Portable SSD 1TB
  • Crucial Portable SSD X8 1TB
  • DIY Plugable USBC-NVME and MyDigitalSSD SBX 1TB
  • Lexar SL100 Pro 1TB
  • OWC Envoy Pro EX USB-C 2TB

A quick overview of the internal capabilities of the storage devices is given by CrystalDiskInfo.

Drive Information

CrystalDiskInfo allows us insight into the internal drive without opening up the unit. The most interesting aspects to note include the fact that UASP is supported by all drives, and all except the Plugable USBC-NVME and the Lexar SL100 Pro support NVMe 1.3.

Testbed Setup and Testing Methodology

Evaluation of DAS units on Windows is done with a Hades Canyon NUC configured as outlined below. We use one of the rear USB Type-C ports enabled by the Alpine Ridge controller for both Thunderbolt 3 and USB devices.

AnandTech DAS Testbed Configuration
Motherboard Intel NUC8i7HVB
CPU Intel Core i7-8809G
Kaby Lake, 4C/8T, 3.1GHz (up to 4.2GHz), 14nm+, 8MB L2
Memory Crucial Technology Ballistix DDR4-2400 SODIMM
2 x 16GB @ 16-16-16-39
OS Drive Intel Optane SSD 800p SSDPEK1W120GA
(118 GB; M.2 Type 2280 PCIe 3.0 x2 NVMe; Optane)
SATA Devices Intel SSD 545s SSDSCKKW512G8
(512 GB; M.2 Type 2280 SATA III; Intel 64L 3D TLC)
Chassis Hades Canyon NUC
PSU Lite-On 230W External Power Brick
OS Windows 10 Enterprise x64 (v1909)
Thanks to Intel for the build components

Our evaluation methodology for direct-attached storage devices adopts a judicious mix of synthetic and real-world workloads. While most DAS units targeting a particular market segment advertise similar performance numbers and also meet them for common workloads, the real differentiation is brought out on the technical side by the performance consistency metric and the effectiveness of the thermal solution. Industrial design and value-added features may also be important for certain users. The reamining sections in this review tackle all of these aspects after analyzing the features of the drives in detail.

Device Features and Characteristics
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  • 13Gigatons - Wednesday, January 29, 2020 - link

    I can't believe how stupid their marketing department is...who's naming this stuff?
    How about: USB 5 and USB 10 and USB 20 and USB 40
  • regsEx - Thursday, January 30, 2020 - link

    There shouldn't be any Gen 1, Gen 1x1, Gen 2, Gen 2x1, SS, SS10, SS20. There should have been only USB 3.0, USB 3.1 and USB 3.2.

    USB Group does it on purpose. To fool people into new shiny numbers.
  • regsEx - Thursday, January 30, 2020 - link

    There shouldn't be any Gen 1, Gen 1x1, Gen 2, Gen 2x1, Gen 2x2, SS, SS10, SS20*
  • Chrestos SV1GAP - Tuesday, March 10, 2020 - link

    The same problem exists with SD cards. After classes 2, 4 ,6, 10 there should be classes 30, 60, 90. Instead of that, there are 3 different names for the class 10 and 2 different names for the classes 6 and 30. https://www.sdcard.org/developers/overview/speed_c...
  • Eliadbu - Tuesday, January 28, 2020 - link

    By the drive speeds I guess it's USB 3.2 gen 2x1 and not gen 2x2 (thanks for the simple naming scheme USB-IF) also makes wonder why there is around 15-20% overhead of the maximum connection speed ( I know it exits in other connections like SATA for example but I wonder why it is so high)
  • amnesia0287 - Thursday, April 9, 2020 - link

    They all seemed to use the same usb chip, so probably that is it’s max speed.
  • Leo222 - Wednesday, March 4, 2020 - link

    Interested in the topic, decided to read, found the first site: https://www.bestadvisor.com/external-solid-state-d...
    And here they write: However, the WD My Passport SSD is uniquely compatible with pretty much all generations of computers. Since it uses the USB 3.1 Gen-2 interface
    It's like the media is truth mixed with fiction, I think it was invented only in order to attract attention and money
  • Chrestos SV1GAP - Tuesday, March 10, 2020 - link

    @ Author, Ganesh T S
    Page 6: "USB 2.0 ports are guaranteed to deliver only 4.5W (900mA @ 5V)".
    You mean "USB 3.0".

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