OWC has been a key player in the storage industry over the last few decades, particularly for Apple users. The company's lineup of portable flash-based direct-attached storage devices has a great reputation in the market, thanks to their focus on performance consistency for professional workloads. OWC is also known for being upfront about their products' capabilities under worst-case conditions.

Back in 2016, the company launched the OWC Envoy Pro Mini - a USB 3.0 Type-A thumb drive with speeds of up to 410 MBps. The lineup topped out at 240 GB. Recently, the company resurrected the product lineup with a complete re-design. The new version comes in capacities between 250 GB and 1 TB, and can support USB 3.2 Gen 2 (10 Gbps) speeds. It sports both Type-A and Type-C interfaces in a sleek and compact thumb drive form factor.

The high-performance thumb drive segment has been dominated for the last several quarters by Kingston's DataTraveler Max, thanks to its first mover advantage. Kingston introduced the Type-C version first and followed it up with a Type-A variant a few quarters down the line. This review takes a detailed look at the performance and value proposition of the 1TB version of the new OWC Envoy Pro Mini, with a particular focus on how it stacks up against the incumbent leader in the segment.

Introduction and Product Impressions

Bus-powered direct-attached storage devices have grown both in storage capacity and 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 and USB 3.2 Gen 2x2), the market has seen the introduction of palm-sized flash-based storage devices capable of delivering 2GBps+ speeds.

The thumb drive form factor is attractive for multiple reasons - there is no separate cable to carry around, and the casing can be designed to include a keyring loop for portability. Vendors such as Corsair and Mushkin briefly experimented with SATA SSDs behind a USB bridge chip, but the thermal solution and size made the UFDs slightly unwieldy. The introduction of high-performance native UFD controllers last year from Phison and Silicon Motion has made this category viable again. On the Phison front, we reviewed the Crucial X6 in August 2021, but it was not a true thumb drive. Silicon Motion has enjoyed significant success in this market segment, thanks to the popularity of the Kingston DataTraveler Max series (with separate SKUs for Type-C and Type-A drives). A few months back, OWC brought back their Envoy Pro Mini into the market with a complete re-design in a bid to wrest share in the high-performance thumb drive category.

The new OWC Envoy Pro Mini aims to differentiate itself from other high-performance thumb drives based on the following aspects:

• Dual interface support in a single unit (both Type-A and Type-C)
• Reduced width to keep adjacent USB ports free for use
• Aluminum enclosure for solidity and improved thermal performance
• Detachable lanyard support, and interface ports protection when not in active use

Despite its thumb drive form-factor, the OWC Envoy Pro Mini takes full advantage of its USB 3.2 Gen 2 connector by promising speeds of up to 946 MBps. It is available in three capacities - 250GB, 500GB, and 1TB. The company sampled us their 1TB version, and we set out to put the drive through our direct-attached storage test suite.

Prior to going into the industrial design and performance, a look at the package contents is warranted. OWC includes the lanyard in the box. It is a detachable one - the lanyard with the thumb drive at the end can be worn around the neck or attached to a bag. However, the clasp closer to the drive end can be easily detached for connecting it to the host system. The company also includes a quick start guide and a key for a 1-year subscription to Acronis Cyber Protect Home Office.

The core component of the Envoy Pro Mini is a simple Type-A flash drive with a muted blue LED indicator behind a plastic tab at the end. This component has screw holes on which two Torx screws can be mounted. The other main component is the Type-A to Type-C adapter that adopts a similar design style to the core component. This adapter includes two slide areas within which the screw holes are aligned prior to putting the Torx screws in place. The areas are long enough to allow the core component to swivel around and complete a 360° rotation. Even though the screw holes are symmetric (allowing the core component to be placed upside down as well), only one orientation of the component allows for it to connect properly with the Type-A receptacle in the adapter. At the other end of the adapter component is the Type-C male port with a cap that allows the lanyard to connect to it. This industrial design is brought out in the gallery below.

OWC assumes that the users of the OWC Envoy Pro Mini are not tech savvy - fair enough, if the intent is to cater to a wide variety of consumers. Once connected to the computer, the thumb drive has one visible FAT32 partition which includes setup files (OWC Drive Guide) for both Windows and Mac operating systems. Ordinarily, I would have gotten rid of all the partitions and formatted the drive in exFAT to proceed further. However, to bring out the setup process for the average consumer, I played along for a bit.

The Drive Guide formats the thumb drive in NTFS for Windows. At this point in time, we believe OWC ought to update this to exFAT. There is also the option to go for the installation of the value addition - 'Acronis Cyber Protect Home Office' (the key for which is included in the package contents). This software includes all the features of 'Acronis True Image' and more (keeping up with the cloud-connected times). It is tangentially related to the actual hardware being purchased - with the ability to make backups and full images of external storage devices. Unfortunately, as with every software of this kind nowadays, the license is subscription-based, and the included key is valid only for one year.

Coming back to the product itself, the industrial design is subjectively excellent, and the metal enclosure lends a solid feel (unlike the flimsy plastic construction of the Kingston DataTraveler Max). Despite integrating both Type-A and Type-C interfaces, the unit is smaller in both length and width. The unit is thicker, but that doesn't negatively affect usage. Congestion is more of an issue for horizontally aligned ports, and the Envoy Pro Mini is better off compared to everything else in its performance class.

There was no obvious way to tear down the sample beyond removing the Torx screws and separating the core and adapter components. Unfortunately, this did not lead us any closer to determining the controller and flash used in the product. However, CrystalDiskInfo provides a quick overview of the capabilities of the storage device. A look at the firmware version (UHFM00.3) and a cursory online search revealed that the OWC Envoy Pro Mini is powered by the Phison U17 controller.

Prior to looking at the benchmark numbers, power consumption, and thermal solution effectiveness, a description of the testbed setup and evaluation methodology is provided.

Testbed Setup and Evaluation Methodology

Direct-attached storage devices (including thumb drives) 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 Kingston DTMAXA drives in these benchmarks. Prior to providing concluding remarks, we have some observations on the UFD'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 Benchmarks - ATTO and CrystalDiskMark

OWC claims speeds of up to 946 MBps for the Envoy Pro Mini. While these are not hit easily under the typical 128KB transfer sizes, the ATTO benchmarks below show that the claimed numbers can indeed be hit under specific conditions. It must be noted that 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

In terms of the overall PCMark score, the Envoy Pro Mini comes with a passable score, but its firmware is not optimized for these types of use-cases. Only the Files Transfers workload component bears relevance to OWC's focus with this product, and the numbers in that don't contribute enough to prevent the Envoy Pro Mini from dropping to the bottom of the pack.

Miscellaneous Aspects and Concluding Remarks

The performance of the storage bridges / drives 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 Mini 1TBOWC Envoy Pro Elektron 1TBKingston DTMAXA/1TBSamsung T7 Touch 1TBKingston DT Max 1TB	BOTTOM: OWC Envoy Pro Elektron 1TBKingston DTMAXA/1TBSamsung T7 Touch 1TBKingston DT Max 1TBOWC Envoy Pro Mini 1TB

A peak of just 1.83W is impressive for the Envoy Pro Mini, and the drive can pretty much turn itself off and idle at close to 0W after around 20 minutes of traffic absence. We do see garbage collection kick in automatically after extended idling (causing the power numbers to spike), and that helps keep the drive in good fettle over the long run. In comparison, the DataTraveler Max SKUs peak at 2.31 W (Type-A) and 3.05 W (Type-C). It must be noted here that we tested the power consumption numbers with the Type-C adapter active.

Final Words

The OWC Envoy Pro Mini has been available for purchase for a couple of quarters now. The street prices are $78 (250 GB), $90 (500 GB), and $130 (1 TB). A comparison of the DataTraveler Max prices at the corresponding capacity points shows that OWC places a premium on the enclosure design - the gap is around $40 for the 250 GB version, and it progressively becomes smaller to just $24 for the 1 TB version. For the premium, the end user gets a highly durable and attractive enclosure that is compatible with a wide variety of computing devices (thanks to its dual interface support). The internal flash device also performs more consistently for stressful workloads.

The Envoy Pro Mini was compared against a host of other 1 TB external flash drives in the preceding sections. However, the key comparison is within its own niche, where it goes up against the Kingston DataTraveler Max. For short bursts, the DataTraveler Max comes out on top in almost all types of workloads. However, under extended use conditions, the Envoy Pro Mini delivers higher absolute performance numbers. This puts more stress on the thermal design, and the Envoy Pro Mini manages to handle it. Despite the higher temperatures during the course of use, the drive does not throttle.

On the internal configuration front, the Envoy Pro Mini delivered a nice surprise. When the Phison U17 was launched in early 2021 after having been teased at the 2019 Computex, its claimed performance numbers were rather anemic. Understandably, this native UFD controller was relegated to the mid-range and entry-level offerings. With NAND layer counts and performance numbers ramping up at a steady pace, it is likely that the U17 has seen some minor updates to support the latest NAND generations - OWC is probably using the new NAND to deliver performance numbers that surpass Phison's initial claims easily. Similar to previous Phison designs from OWC, the SLC cache is rather small. We would like to see SLC cache sizes in the 10% range (rather than the 2.4% adopted for the 1 TB model) as long as other performance metrics (particularly in the extended stress scenario) are not negatively affected.

OWC deserves plaudits for bucking the usual trend of vendors trying to slap on the the highest possible performance numbers in the product packaging. In our opinion, the slightly lower peak performance numbers are more than made up for by the performance consistency under extended use, as well as optimized power consumption numbers (particularly when used with battery-operated devices). Overall, the Envoy Pro Mini has come out as a credible challenger to the pole position enjoyed by the Kingston DataTraveler Max series in the 'SSD in a thumb drive' market segment.