The market for portable SSDs has shown rapid growth over the past decade or so. Almost all tier-one flash vendors (including Samsung, Western Digital / SanDisk, Micron / Crucial, and SK hynix) have their own PSSD lineup. Other than SK hynix, the others in the list have multiple PSSD models in the market. This has allowed them to target different market segments in terms of performance / serviced use-cases and cost. Samsung was one of the first tier-one vendors to pay attention to this market with the launch of the T1 Portable SSD in 2015. Since then, the company has been regularly introducing new PSSD models in the T series, while also launching the Thunderbolt-compliant X5.

The T5 EVO Portable SSD being launched today by Samsung heralds a new category in the PSSD space - high-capacity flash storage limited to entry level speeds. The minimum capacity point in the T5 EVO PSSD family is 2 TB, with options for the consumer to scale up to 4 TB and 8 TB based on user requirements. Pricing is kept reasonable by the use of QLC flash. Samsung is no strager to using QLC flash in high-capacity consumer storage products. The 860 QVO and 870 QVO SATA SSDs were launched in 2018 and 2020 with a 8 TB version at the high end in the latter. Samsung's use of dynamic SLC caching ('Intelligent TurboWrite' in their marketing parlance (PDF)) allowed these drives to offer compelling $/TB metrics while delivering enough performance for day-to-day PC usage. However, the performance after running out of the SLC cache was abysmal and even worse than 2.5" hard drives.

The T5 EVO PSSD is not the first in the market to use QLC flash. Sabrent had used QLC flash in their lineup of dual-mode (Thunderbolt + USB) drives marketed under the XTRM Q tag. While the 4 TB and 8 TB capacity options for the XTRM Q were extremely attractive, and pricing was not outright ridiculous, the performance of the drives did not keep up with user expectations (particularly from the viewpoint of a Thunderbolt drive). Samsung is wisely avoiding this mis-step by limiting the T5 EVO to 5 Gbps speeds with its USB 3.2 Gen 1 Type-C connector. Can limiting the interface speeds for a QLC PSSD deliver better user experience? Samsung sent across the 8 TB variant of the T5 EVO to put through our rigorous direct-attached storage evaluation process. The review below investigates the performance profile of the PSSD sample and provides some comments on its value proposition.

Introduction and Product Impressions

The market for bus-powered direct-attached storage devices has expanded considerably over the last few years. Rapid advancements in 3D NAND technology, coupled with increasing confidence of manufacturers in QLC (4-bits per cell) has driven down the $/TB metric for capacious SSDs. On the host interface front, updates to the maximum speed have been clocking in at regular intervals. While USB 2.0 with its 480 Mbps speed held sway for more than 8 years, successive updates to 5 Gbps, 10 Gbps, 20 Gbps, 40 Gbps, and 80 Gbps have been introduced with a gap of 3 to 4 years between them. From the perspective of bus-powered storage devices, distinctive categories have emerged depending on the performance profile and internal components.

  • 3GBps+ class: USB4 SSDs
  • 2.5GBps+ class: Thunderbolt SSDs with PCIe 3.0 x4 NVMe drives
  • 2GBps+ class: USB 3.2 Gen 2x2 SSDs with PCIe 3.0 x4 NVMe drives or native UFD controllers
  • 1GBps+ class: USB 3.2 Gen 2 SSDs with PCIe 3.0 (x4 or x2) NVMe drives or native UFD controllers
  • 500MBps+ class: USB 3.2 Gen 2 SSDs with SATA drives or native UFD controllers
  • 400MBps+ class: USB 3.2 Gen 1 SSDs with SATA drives or native UFD controllers
  • Sub-400MBps+ class: USB 3.2 Gen 1 flash drives with direct flash-to-USB (native UFD) controllers

The recent spate of product introductions has been in the first four categories, with a push for native UFD controllers that offer power consumption and thermal performance advantages. Therefore, it came as a bit of a surprise when Samsung sent across the details of the T5 EVO Portable SSD in the 400MBps+ class. The company is pitching the capacity options as the key selling point.

The T5 EVO is a 102g 95mm x 40mm x 17mm USB 3.2 Gen 1 PSSD made of solid metal with a rubber sleeve. The casing includes a metal ring for a lanyard, making it easy to carry around without fear of misplacing the drive. The T5 EVO's dimensions make it appear to be a thick and oversized thumb drive (without the protruding connector), but the full metal construction lends it enough weight to give users a solid feel when handling it. The unit includes a blue LED power indicator near the upstream Type-C port. The rubber covering provides it extra durability against external shocks (Samsung claims drop testing from a height of 2m, but the 3-year warranty doesn't cover physical damage caused by mishandling). Samsung includes a single 46cm USB 3.2 Gen 1 Type-C to Type-C cable in the package.

Samsung's 8TB 870 QVO SATA SSD has been in the market for a few years. Given a similar capacity point, and performance numbers below that of the 870 QVO (due to host interface limitations), we suspected that the T5 EVO platform would share a lot in common with the 870 QVO. Our suspicions were not unfounded, as shown in the teardown gallery below.

The internals of the T5 EVO are kept hidden away by a number of screws under different plastic overlays. After figuring out their locations and unscrewing them, the rubber sleeve could be removed to reveal the solid metal casing. Removal of four easy-to-spot screws on the underside of the metal case allows the two layers of the casing to become unclasped. This reveals the single-board solution, whose components are protected by thermal pads that lie tight against the metal casing under normal circumstances.

Similar to the 870 QVO, the 8TB T5 EVO incorporates four flash packages (two on each side of the board, as shown in the gallery). However, the part numbers are different. While the 870 QVO used the K9XVGB8J1A, the T5 EVO uses the K9YYGB8J1C (visible at the bottom of the board photograph above). The 870 QVO used Samsung's 9XL 3D V-NAND in QLC mode, but the new flash part number belongs to a different generation (likely decoding to 136L decoding to 7th Gen. -  176L - 3D V-NAND in QLC mode). The SATA controller (S4LR069 Metis) remains the same as the 870 QVO as does the presence of 8GB of LPDDR4 RAM for flash translation layer usage. The obvious additional component is the bridge chip - the ASMedia ASM235CM which bridges a single downstream SATA III port with a USB 3.2 Gen 1 (5 Gbps) Type-C upstream port.

The Samsung T5 EVO PSSD also includes hardware encryption support. Users can equip the PSSD with a password set via the Samsung Magician software.

CrystalDiskInfo provides a quick overview of the capabilities of the internal storage device. TRIM and NCQ are seen in the features list. The benchmark numbers in the next section confirm that native command queuing is active in the PSSD, and all S.M.A.R.T features such as temperature read outs worked well.

S.M.A.R.T Passthrough - CrystalDiskInfo

The table below presents a comparative view of the specifications of the different storage bridges presented in this review.

Comparative Direct-Attached Storage Devices Configuration
Downstream Port 1x SATA III 1x PCIe 3.0 x4
Upstream Port USB 3.2 Gen 1 Type-C (Female) USB 3.2 Gen 2x2 Type-C (Female)
Bridge Chip ASMedia ASM235CM ASMedia ASM2364
Power Bus Powered Bus Powered
Use Case 5Gbps-class, ultra high-capacity, compact, and sturdy portable SSD with a Type-C interface 2GBps-class, sturdy palm-sized high-performance portable SSD with a Type-C interface
Physical Dimensions 95 mm x 40 mm x 17 mm 88 mm x 60 mm x 14 mm
Weight 102 grams 122 grams
Cable 46 cm USB 3.2 Gen 1 Type-C (male) to Type-C (male) 45 cm USB 3.2 Gen 2x2 Type-C (male) to Type-C (male)
45 cm USB 3.2 Gen 2 Type-C (male) to Type-A (male)
S.M.A.R.T Passthrough Yes Yes
UASP Support Yes Yes
TRIM Passthrough Yes Yes
Hardware Encryption Yes Yes
Evaluated Storage Samsung 176L V-NAND (7th Gen.) QLC Samsung 176L V-NAND (7th Gen.)
Price $650 $440
Review Link Samsung T5 EVO 8TB Review Samsung T9 Portable SSD 4TB Review

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 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 2021 AnandTech DAS Testbed Configuration
System Intel Quartz Canyon NUC9vXQNX
CPU Intel Xeon E-2286M
Memory ADATA Industrial AD4B3200716G22
32 GB (2x 16GB)
DDR4-3200 ECC @ 22-22-22-52
OS Drive ADATA Industrial IM2P33E8 NVMe 1TB
Secondary Drive SanDisk Extreme PRO M.2 NVMe 3D SSD 1TB
Add-on Card SilverStone Tek SST-ECU06 USB 3.2 Gen 2x2 Type-C Host
OS Windows 10 Enterprise x64 (21H1)
Thanks to ADATA, Intel, and SilverStone Tek for the build components

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 couple of sections, we have an overview of the performance of the 8TB variant of the Samsung T5 EVO PSSD 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
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  • James5mith - Tuesday, November 14, 2023 - link

    "The T5 EVO is able to sustain maximum write speeds (around 440 MBps) for more than three hours"

    By your own graph, 180 seconds does not equate to 3 hours.
  • DanNeely - Saturday, November 18, 2023 - link

    You're looking at the wrong graph. The t5 EVO is the top one in the pair by that comment and sustains the 440MBps speed for ~13000 seconds (3.6 hours). The bottom graph is for the comparison SSD, which sustains ~1700MBps for 3 minutes before falling down to ~900MBps.
  • James5mith - Tuesday, November 14, 2023 - link

    Sorry, I guess I was looking at the T9 graph while reading the paragraph. My mistake.
  • GabrielFerrazTPU - Tuesday, November 14, 2023 - link

    Hello my name is Gabriel Ferraz i'm the computer engineer responsible for the Techpowerup SSD Database, first of all, great job on the review, just as an insight, i'm not sure which decoder you used on that NAND Flash, but i think it's the newer 176-Layer QLC Die, i didn't see any QLC 128-Layer NAND Flash from Samsung so far. only the 512Gb / 256Gb TLV V6 and the TLC V6P (Prime) 133-Layer 512Gb
  • Slash3 - Tuesday, November 14, 2023 - link

    The TPU database is a great resource; we appreciate the work that goes into it!
  • GabrielFerrazTPU - Thursday, November 16, 2023 - link

    Thank you :)
    I'm glad you guys liked it
  • ganeshts - Tuesday, November 14, 2023 - link

    Gabriel, Thanks for taking the time to make this observation.

    I've since confirmed that this flash package is indeed 176L 7th Gen. V-NAND QLC, I have updated the article with necessary strike-throughs to reflect this fact.
  • GabrielFerrazTPU - Thursday, November 16, 2023 - link

    You're Welcome :D

    By the way, if you could do me a favor, since i'm from Brazil Samsung don't ship drives here so i can't contact them directly, do you think you could ask them more about their "V6P 133-Layer" line-up? I've recently heard about it a few days ago, but i can't find anything about it.
  • name99 - Tuesday, November 14, 2023 - link

    "However, Samsung is currently selling the PSSD for $650... This is absurd pricing for a QLC PSSD"

    It's only absurd pricing if there is competition. There ISN'T.
    If I want an external 8G SSD drive, what are my options?

    - I can buy a QVO and an enclosure -- but most enclosures don't work with an 8TB drive. (More precisely there seems to be some confusion in the spec around 8TB, so for any random combination of 8TB drive, enclosure, PC, and OS, it's random whether it works or not)

    - I can buy a VectoTech drive which is, admittedly, cheaper, but probably of weaker performance, especially for large writes.
    - Or I can buy an Oyen drive of even more unknown characteristics.

    That's it.

    The Samsung price will come down when brands that people have actually heard of enter the market. So far, for whatever reason, that simply hasn't happened. No Crucial, no Kingston, no PNY, no Sandisk.
  • ganeshts - Tuesday, November 14, 2023 - link

    Yes, once there is more competition from known brands in the 8TB space, the pricing will come down. But, that doesn't explain why the T9 4TB SKU is currently at $250 in both Best Buy and Amazon, while Samsung wants to charge $350 for the 4TB T5 EVO (on Amazon again).

    Pricing a QLC PSSD more at the same capacity as a TLC PSSD (with a faster host interface) is absurd. Samsung needs to go back to the drawing board as far as pricing is concerned.

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