Samsung's lineup of portable SSDs has enjoyed tremendous success, starting with the T1 back in 2015. The company has been regularly updating their PSSD lineup with the evolution of different high-speed interfaces as well as NAND flash technology.

Earlier this year, Samsung launched the Portable SSD T7 Shield, a follow-up to the Portable SSD T7 (Touch) introduced in early 2020. Samsung is mainly advertising the ruggedness / IP65 rating of the T7 Shield as a selling point over the regular Portable SSD T7 and T7 Touch. Today's review takes a look at the performance and value proposition of the Portable SSD T7 Shield. Our detailed analysis in the review below reveals another trick that Samsung has up their sleeve, which makes the T7 Shield a worthy successor (rather than just an addition) to the Portable SSD T7 family.

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 of 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 or USB4, 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 Samsung Portable SSD T7 Shield we are looking at today belongs to the third category in the above list, utilizing a NVMe SSD behind an ASMedia ASM2362 bridge chip. The configuration is quite similar to the Portable SSD T7 (Touch) in terms of the NVMe controller and the bridge chip. There are a few industrial design updates to protect the drive against dust ingress and splashes of water (IP65), as well as lend it an element of ruggedness. The striking externally visible one is the addition of an elastomer covering (available in beige, blue, and black) to the internal metal case. The new casing also has a few ridges that run across the longer side.

Samsung includes two separate cables - one USB Type-C to Type-A, and another Type-C to Type-C of approximately the same length. Disassembling the unit is fairly trivial after taking out the four screws hidden under the product label stickers on either side, and removing the elastomer covering. This reveals an aluminum metal enclosure. The plastic tray holding the actual PSSD board can then be slid out after the removal of the plastic piece opposite the connector end. Both plastic end pieces have grommets around their periphery to ensure a good seal and contribute to the IP65 rating. The main board is held on to the plastic tray by four smaller screws. The connector on the main board has a red-colored sealing band to ensure that it doesn't become an ingress point for external material.

A full teardown gallery is also presented above. It shows that one side of the board is covered with a thermal pad despite having no components on its side. The removal of the thermal pad on the other side reveals the controller and the flash packages. The SSD controller is the S4LR033, and the ASMedia ASM2362 bridge chip is right next to it. The SSD subsysem in the PSSD T7 Shield is a DRAM-less one, and is pretty much the same as that of the T7 Touch - except for the flash packages. The two flash chips on board have the K9DVGB8J1B tag (against the K9DVGY8J5A in our sample of the PSSD T7 Touch). This part number decodes as: TLC, 6th gen V-NAND (128L / 136T), 512Gbit per die, 16 dies, 1TB for the whole package. This is the same NAND package used in Samsung 870 EVO SATA SSD.

Moving from the 5th Gen. 92L (96T) V-NAND in the T7 Touch to the 6th Gen. 128L (136T) V-NAND brings about a 10% improvement in latency and 15% reduction in power consumption, as per Samsung's claims. As we shall discovered further down in this review, these aspects do bear out when looking at various evaluation results.

The review compares the Samsung Portable SSD T7 Shield 2TB against the other 2TB drives reviewed earlier using our latest direct-attached storage test suite. We have also added the Samsung Portable SSD T7 Touch 1TB to the mix, even though it doesn't make for an apples-to-apples comparison. The list of PSSDs considered in this review is provided below.

• Samsung T7 Shield 2TB
• SanDisk Professional G-DRIVE 2TB
• SanDisk Professional G-DRIVE ArmorLock 2TB
• Kingston XS2000 2TB
• Samsung T7 Touch 1TB

A quick overview of the internal capabilities of the storage devices is given by CrystalDiskInfo. The Samsung PSSD T7 Shield supports full S.M.A.R.T passthrough, along with TRIM to ensure consistent performance for the drive over its lifetime.

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 portable SSDs) 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 direct-attached storage devices 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 Samsung Portable SSD T7 Shield in these benchmarks. Prior to providing concluding remarks, we have some observations on the PSSD'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

Samsung claims read and write speeds of 1050 MBps and 1000 MBps respectively, 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 256KB 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 Samsung T7 Shield lands right in the middle of the pack. Among the 1GBps-class PSSDs, the drive loses out only to the DRAM-equipped SanDisk Professional G-DRIVE.

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 section. 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: Samsung T7 Shield 2TBSDP G-DRIVE 2TBSDP G-DRIVE ArmorLock 2TBKingston XS2000 2TBSamsung T7 Touch 1TB	BOTTOM: SDP G-DRIVE 2TBSDP G-DRIVE ArmorLock 2TBKingston XS2000 2TBSamsung T7 Touch 1TBSamsung T7 Shield 2TB

In terms of overall average power consumption and ability to enter really deep sleep, the Kingston XS2000 is the clear winner because of its native UFD controller. Among the bridge-based solutions, the T7 Touch has the lowest peak, but it is the T7 Shield that ends up with the lowest active region average. In the deep sleep stage (entered after around 20 minutes of no activity), the drive consumes only 0.12W - almost half of what the T7 Touch was able to reach.

Concluding Remarks

The Samsung Portable SSD T7 Shield has been available for purchase for a few months now. The official launch MSRP for the 2TB version was $234, but the drive has been on sale for $200 for a few days now. At this price, the PSSD delivers excellent value for money for typical direct-attached storage workloads. The ruggedness / IP65 rating, as well as low power consumption, are added icing on the cake. With hardware encryption support (enabled by the Samsung Portable SSD Software), the use-cases for the PSSD are manifold. The main competition for the drive comes in the form of the SanDisk Professional G-DRIVE SSD - it carries an IP67 rating for a slight premium. While the T7 Shield is able to win out on typical DAS workloads, the DRAM-equipped SSD in the G-DRIVE provides slightly better performance for typical SSD workloads such as application launches and read/writes of small files.

On scope for improvement, Samsung would do well to explore DRAM-equipped PSSDs in a slightly premium line - those could deliver better performance for non-DAS workloads (and PSSDs are starting to get treated on par with internal SSDs by power users already). They could also explore supplying a single Type-C to Type-C cable along with an attached Type-C to Type-A adapter (similar to the solution delivered by manufacturers like OWC in their Envoy Pro).

The silent star of the T7 Shield show is actually the update to the internal flash. The move to 6^th Gen. 128L (136T) V-NAND has enabled the T7 Shield to provide unparalleled performance consistency in its class for typical DAS workloads, while maintaining excellent thermals and low power consumption. In our opinion, the improvements in the T7 Shield over the T7 / T7 Touch are significant enough to call it a worthy successor, rather than just an addition to the T7 family.