The market for portable SSDs has expanded significantly over the past few years. With USB 3.2 Gen 2 (10 Gbps) becoming the de-facto standard for USB ports even in entry-level systems, external storage devices using the interface have flooded the market.

OWC has established itself as vendor of computing peripherals and upgrade components (primarily for the Apple market) over the last 30 years. Their portable SSDs lineup, under the Envoy brand, includes both Thunderbolt and USB-C offerings. The Envoy Pro EX Thunderbolt 3 and the Envoy Pro EX USB-C coupled leading performance numbers with a sleek and stylish industrial design. Late last year, the company introduced the OWC Envoy Pro Elektron - a portable flash drive similar to the Envoy Pro EX USB-C in performance, albeit in a much smaller form-factor.

This review presents results from processing our updated test suite for direct-attached storage devices on the OWC Envoy Pro Elektron 1TB drive.

Introduction and Product Impressions

External, bus-powered storage devices capable of 1GBps+ performance have become entry-level offerings in the market today. Rapid advancements in flash technology (including the advent fo 3D NAND and NVMe) as well as faster host interfaces (such as Thunderbolt 3 and USB 3.2 Gen 2+) have been key enablers. Broadly speaking, there are five distinct performance levels in this market:

• 2GBps+ drives with Thunderbolt 3, using NVMe SSDs
• 2GBps drives with USB 3.2 Gen 2x2, using NVMe SSDs or direct USB flash drive (UFD) controllers
• 1GBps drives with USB 3.2 Gen 2, using NVMe SSDs or direct UFD controllers
• 500MBps drives with USB 3.2 Gen 1 (or, Gen 2, in some cases), using SATA SSDs
• Sub-400MBps drives with USB 3.2 Gen 1, using UFD controllers

The OWC Envoy Pro Elektron we are looking at today belongs to the third category in the above list, utilizing a M.2 2242 NVMe SSD behind the ASMedia ASM2362 bridge chip. The compact casing is all-metal, and the drive is IP67 rated for protection against dust ingress and water immersion.

OWC includes a single Type-C to Type-C cable along with a permanently attached Type-C to Type-A adapter in the package. Disassembling the unit is fairly trivial, with four Torx screws under the rubber bumper needing removal.

The internal layout, rubber grommets for ingress protection, and the placement of the thermal pads is very similar to the Sabrent Rocket Nano we reviewed last year, but the main board has a significant difference - an ASMedia ASM2362 bridge chip in place of the JMicron JMS583. In addition, the industrial design of the Envoy Pro Elektron is subjectively more stylish than the regular rectangular block design of the Rocket Nano. Both portable SSDs re-use their branded Phison-based M.2 2242 NVMe SSDs inside the enclosure. In the case of the Elektron, it is the OWC Aura P13 Pro.

The review compares the OWC Envoy Pro Elektron 1TB against the other 1TB drives reviewed earlier using our 2021 direct-attached storage test suite.

• OWC Envoy Pro Elektron 1TB
• Akasa AK-ENU3M2-04 (SK hynix Gold P31 1TB behind a Realtek RTL9210G bridge)
• Akasa AK-ENU3M2-03 (SK hynix Gold P31 1TB behind an ASMedia ASM2362 bridge)
• Kingston DT Max 1TB

A quick overview of the internal capabilities of the storage devices is given by CrystalDiskInfo. The OWC Envoy Pro Elektron supports full S.M.A.R.T passthrough, along with TRIM to ensure consistent performance for the drive over its lifetime.

Testbed Setup and Evaluation Methodology

Direct-attached storage devices (including portable SSDs like the OWC Envoy Pro Elektron) are evaluated using the Quartz Canyon NUC (essentially, the Xeon / ECC version of the Ghost Canyon NUC) configured with 2x 16GB DDR4-2667 ECC SODIMMs and a PCIe 3.0 x4 NVMe SSD - the IM2P33E8 1TB from ADATA.

The most attractive aspect of the Quartz Canyon NUC is the presence of two PCIe slots (electrically, x16 and x4) for add-in cards. In the absence of a discrete GPU - for which there is no need in a DAS testbed - both slots are available. In fact, we also added a spare SanDisk Extreme PRO M.2 NVMe SSD to the CPU direct-attached M.2 22110 slot in the baseboard in order to avoid DMI bottlenecks when evaluating Thunderbolt 3 devices. This still allows for two add-in cards operating at x8 (x16 electrical) and x4 (x4 electrical). Since the Quartz Canyon NUC doesn't have a native USB 3.2 Gen 2x2 port, Silverstone's SST-ECU06 add-in card was installed in the x4 slot. All non-Thunderbolt devices are tested using the Type-C port enabled by the SST-ECU06.

The specifications of the testbed are summarized in the table below:

The testbed hardware is only one segment of the evaluation. Over the last few years, the typical direct-attached storage workloads for memory cards have also evolved. High bit-rate 4K videos at 60fps have become quite common, and 8K videos are starting to make an appearance. Game install sizes have also grown steadily even in portable game consoles, thanks to high resolution textures and artwork. Keeping these in mind, our evaluation scheme for portable SSDs and UFDs involves multiple workloads which are described in detail in the corresponding sections.

• Synthetic workloads using CrystalDiskMark and ATTO
• Real-world access traces using PCMark 10's storage benchmark
• Custom robocopy workloads reflective of typical DAS usage
• Sequential write stress test

In the next section, we have an overview of the performance of the OWC Envoy Pro Elektron in these benchmarks. Prior to providing concluding remarks, we have some observations on the drive's power consumption numbers and thermal solution also.

Performance Benchmarks

Benchmarks such as ATTO and CrystalDiskMark help provide a quick look at the performance of the direct-attached storage device. The results translate to the instantaneous performance numbers that consumers can expect for specific workloads, but do not account for changes in behavior when the unit is subject to long-term conditioning and/or thermal throttling. Yet another use of these synthetic benchmarks is the ability to gather information regarding support for specific storage device features that affect performance.

Synthetic Benchmark - ATTO

OWC claims speeds of up to 1011 MBps, and these are backed up by the ATTO benchmarks provided below. ATTO benchmarking is restricted to a single configuration in terms of queue depth, and is only representative of a small sub-set of real-world workloads. It does allow the visualization of change in transfer rates as the I/O size changes, with optimal performance being reached around 512 KB for a queue depth of 4.

Full System Drive Benchmark Bandwidth (MBps)Full System Drive Benchmark Latency (us)Full System Drive Benchmark ScoreExpand All

The performance of the OWC Envoy Pro Elektron in the PCMark 10 Storage Bench leaves a lot to be desired. The pre-conditioning adopted by the benchmark is likely putting the internal SSD in a state such that it is not able to live up to its potential in the actual workloads. We did see the drive performing in an acceptable manner in our custom workloads, along with the likely reasons (SLC cache size / recovery rate) for not matching DIY solutions or the DT Max. However, the PCMark 10 storage workloads reveal a much wider gulf in the ability of the Elektron to deliver when subject to stressful long-term workloads.

Miscellaneous Aspects and Concluding Remarks

The performance of the OWC Envoy Pro Elektron in various real-world access traces as well as synthetic workloads was brought out in the preceding sections. We also looked at the performance consistency for these cases. Power users may also be interested in performance consistency under worst-case conditions, as well as drive power consumption. The latter is also important when used with battery powered devices such as notebooks and smartphones. Pricing is also an important aspect. We analyze each of these in detail below.

Worst-Case Performance Consistency

Flash-based storage devices tend to slow down in unpredictable ways when subject to a large number of small-sized random writes. Many benchmarks use that scheme to pre-condition devices prior to the actual testing in order to get a worst-case representative number. Fortunately, such workloads are uncommon for direct-attached storage devices, where workloads are largely sequential in nature. Use of SLC caching as well as firmware caps to prevent overheating may cause drop in write speeds when a flash-based DAS device is subject to sustained sequential writes.

Our Sequential Writes Performance Consistency Test configures the device as a raw physical disk (after deleting configured volumes). A fio workload is set up to write sequential data to the raw drive with a block size of 128K and iodepth of 32 to cover 90% of the drive capacity. The internal temperature is recorded at either end of the workload, while the instantaneous write data rate and cumulative total write data amount are recorded at 1-second intervals.

CrystalDiskMark Workloads - Power Consumption
TOP: OWC Envoy Pro Elektron 1TBAkasa AK-ENU3M2-04 (NVMe)Akasa AK-ENU3M2-03Kingston DT Max 1TB	BOTTOM: Akasa AK-ENU3M2-04 (NVMe)Akasa AK-ENU3M2-03Kingston DT Max 1TBOWC Envoy Pro Elektron 1TB

The Elektron does not acquit itself favorably on the power consumption front. We see a peak around 4.8W, and average active power consumption during the course of the workload is north of 2W (slightly more than the DIY solution based on the same bridge chip). The drive also seems to spend a significant amount of time in garbage collection / SLC cache recovery after workload completion (as seen in the 2.5W plateau in the graph), which prevented it from going to sleep in the typical duration taken by other portable drives.

Final Words

The OWC Envoy Pro Elektron is currently on Amazon for $229. The closest competitor to this product is the Sabrent Rocket Nano Rugged at $170. While the review couldn't include direct performance comparison (we do not have data for the 1TB version of the drive), the specifications are similar - a rugged IP67 rating, a Phison E13-based internal SSD, and an all-metal enclosure. The Rocket Nano Rugged also includes a rubber bumper. On the other hand, the OWC has a more stylish industrial design, and bundles an attached Type-C to Type-A adapter with the cable (ensuring ability to use with multiple systems in an easier manner compared to carrying two different cables). It also uses an ASMedia bridge chip (which continues to have a better reputation in the market compared to JMicron's offerings, though we have not observed much of a difference in our own tests). Whether those aspects are worth the additional $60 premium is for consumers to decide.

In terms of performance and consistency, the Envoy Pro Elektron delivers the goods appropriately given its size and form-factor. Custom DIY SSDs with the Akasa enclosures deliver better consistency, but are bulkier and do not possess the ruggedness inherent in the Envoy Pro Elektron. The Kingston DT Max is much lighter and has a thumb-drive form-factor. It delivers more SLC cache - almost 95GB in the 1TB model, compared to the 25GB in the Envoy Pro Elektron, but long-term performance consistency (in terms of direct-to-TLC write speeds) is much better for the OWC unit.

In conclusion, the OWC Envoy Pro Elektron is a premium portable SSD that meets OWC's performance and ruggedness claims. There are cheaper alternatives, and there are units that provide better performance at the cost of compactness and/or consistency. However, the OWC Envoy Pro Elektron provides a unique combination of these aspects, partially justifying the pricing. Such additional options in the market are always welcome from a consumer viewpoint.