Samsung’s Portable SSD T5 reviewed

The density wars are in full swing between the major flash players, and the name of the game is 64-layer 3D NAND. We recently experienced Toshiba’s 64-layer BiCS TLC firsthand in the company’s excellent XG5 SSD. IMFT’s 64-layer stuff is already out on the market in the Intel 545s, but we’ve yet to spend any hands-on time with it. Samsung’s 64-layer V-NAND has been on our radar for just about a year now, but the company has really been talking up a storm about the technology in the last couple of months.

Well, brace yourselves: we’ve made it to the eye of the storm. Today, Samsung officially unveils the first client drive with 64-layer V-NAND inside: the Portable SSD T5. The company was kind enough to send us 500GB and 1TB versions of its latest to run through the wringer.

The T5 closely follows in the footsteps of its forebear, the Portable SSD T3. It retains the same compact size and feathery weight, ringing in at 3 x 2.3″ x 0.4″ and 51 grams. The housing construction has changed slightly in this version, though. The T5 sheds the T3’s two-piece metal and plastic body for an all-aluminum unibody. The 250GB and 500GB versions are finished in, ahem, “Alluring Blue,” while the 1TB and 2TB models are clad in a simpler “Deep Black.”

The big news, of course, is the move from 48-layer TLC V-NAND to the 64-layer stuff. Samsung reckons that the newfound speeds engendered by that transition require outfitting the T5 with a USB 3.1 Gen 2 interface instead of Gen 1. The company claims the T5 can hit peak speeds of 540 MB/s, which should theoretically fit within the 5 Gb/s maximum that USB 3.1 Gen 1 (or USB 3.0, if you prefer) affords. In reality, encoding overhead can be a buzzkill for the older standard. More on that later.

The 500GB drive drew the short straw, so it had to endure being stripped down to its skivvies. The 64-layer TLC V-NAND is distributed across only two packages on the same side of the PCB as the controller. That controller appears to be a variant of the same MGX chip found inside the T3. In a rare but sensible deviation from complete vertical integration, Samsung seems to be passing USB controller duties off to an ASMedia mSATA-to-USB bridge controller.

The T5 supports AES 256-bit hardware encryption, accessible via Samsung’s Portable SSD software. As it did with the T3 before, the software provides easy interfaces for encrypting, decrypting, and updating the drive’s firmware. The software is available for PC, Mac, and Android. Unlike the T3, the T5 includes a USB Type-C to Type-C cable in addition to the vanilla Type-C to Type-A cable, so consuming your encrypted files on-the-go should be dead simple. At the time of this writing, however, the Android app for T5 was not available for experimentation.

Now let’s get down to testing and and bring RoboBench to the stage.


TR RoboBench — Real-world transfers

First, a quick update on our test setup. Our Intel Z97 storage rigs are equipped with mere USB 3.1 Gen 1 ports. Therefore, we secured a Rosewill add-in card to let the T5 run wild at Gen 2 speeds. The card uses the same ASMedia ASM1142 controller that is very commonly found on motherboards with 3.1 Gen 2 capabilities.

You may notice some data in our results from a drive we haven’t yet reviewed: Adata’s SD700. The full review is in the works, but since we already had the raw numbers we decided to include them in our graphs this time around. Stay tuned for our full look at the SD700 soon.

RoboBench comprises real-world transfers with a range of file types. Developed by our in-house coder, Bruno “morphine” Ferreira, this benchmark relies on the multi-threaded robocopy command build into Windows. We copy files to and from a wicked-fast RAM disk to measure read and write performance. We also cut the RAM disk out of the loop for a copy test that transfers the files to a different location on the SSD.

Robocopy uses eight threads by default, and we’ve also run it with a single thread. Our results are split between two file sets, whose vital statistics are detailed below. The compressibility percentage is based on the size of the file set after it’s been crunched by 7-Zip.

  Number of files Average file size Total size Compressibility
Media 459 21.4MB 9.58GB 0.8%
Work 84,652 48.0KB 3.87GB 59%

The media set is made up of large movie files, high-bitrate MP3s, and 18-megapixel RAW and JPG images. There are only a few hundred files in total, and the data set isn’t amenable to compression. The work set comprises loads of TR files, including documents, spreadsheets, and web-optimized images. It also includes a stack of programming-related files associated with our old Mozilla compiling test and the Visual Studio test on the next page. The average file size is measured in kilobytes rather than megabytes, and the files are mostly compressible.

RoboBench’s write and copy tests run after the drives have been put into a simulated used state with 30 minutes of 4KB random writes. The pre-conditioning process is scripted, as is the rest of the test, ensuring that drives have the same amount of time to recover.

Let’s take a look at the media set first. The buttons switch between read, write, and copy results.

The T5 drives immediately set themselves apart from the USB 3.1 Gen 1 drives. Read speeds are a solid 10% ahead of the T1 and SD700, but write speeds are an incredible 50% higher in the single-threaded test. Across read, write, and copy, the T5 is far closer to the SATA 850 EVO 2TB than to any of our older USB drives. 10 Gbps USB is some pretty good stuff.

Next up, the work set.

The story is much the same with the work set, at least with a single thread. The T5 drives seem to dislike reading the work set with eight threads, putting up numbers about 20% worse than the T3 did. But again, write numbers are vastly improved.

The T5 performed better than our USB 3.1 Gen 1 drives across all our tests except one, and it generally won by large margins. Additionally, the 500GB drive’s results were just as good as the 1TB’s. “Alluring Blue” is no misnomer.

Ordinarily we’d be done here, but since we had some extra time, we decided to rerun a few tests with the T5 plugged into one of our motherboard’s USB 3.1 Gen 1 ports to see how much of a difference Gen 2 makes. Let’s take a look.

When mated to a slower Gen 1 port, the T5 500GB’s speeds are almost identical to that of the T3. Samsung’s 64-layer NAND might be bringing some new mojo with it, but it appears that much of the speed increase might be credited to the USB 3.1 Gen 2 upgrade. But without a 48-layer V-NAND device running on Gen 2 to compare against, we can’t definitively attribute the gains to one factor or another.

That’s it for testing. Hit the next page for our test methods, or skip ahead to the conclusion.


Test notes and methods

Here’s are the essential details for all the drives we tested:

  Interface Flash controller NAND
Adata SD700 External SSD USB 3.1 Gen 1 Silicon Motion SM2258 32-layer Micron 3D TLC
Samsung 850 EV0 2TB SATA 6Gbps Samsung MHX 32-layer Samsung TLC
Samsung Portable SSD T3 USB 3.1 Gen 1 Samsung MGX 48-layer Samsung TLC
Samsung Portable SSD T5 USB 3.1 Gen 2 Samsung MGX 64-layer Samsung TLC

USB 3.1 Gen 1 drives were connected to the motherboard via USB 3.0 port. USB 3.1 Gen 2 drives were connected via a 3.1 Gen 2 add-in card. The 2.5″ drives were connected via a USB 3.0 drive dock for SATA drives.

We used the following system for testing:

Processor Intel Core i5-4690K 3.5GHz
Motherboard Asus Z97-Pro
Firmware 2601
Platform hub Intel Z97
Platform drivers Chipset:


Memory size 16GB (2 DIMMs)
Memory type Adata XPG V3 DDR3 at 1600 MT/s
Memory timings 11-11-11-28-1T
Audio Realtek ALC1150 with drivers
System drive Corsair Force LS 240GB with S8FM07.9 firmware
USB 3.1 Gen 2 card Rosewill RC-509
Drive dock StarTech USB 3.1 Single-Bay Dock
Power supply Corsair AX650 650W
Case Fractal Design Define R5
Operating system Windows 8.1 Pro x64

Thanks to Asus for providing the systems’ motherboards, to Intel for the CPUs, to Adata for the memory, to Fractal Design for the cases, and to Corsair for the system drives and PSUs.

We used the following versions of our test applications:

  • IOMeter 1.1.0 x64
  • TR RoboBench 0.2a

Some further notes on our test methods:

  • To ensure consistent and repeatable results, the SSDs were secure-erased before every component of our test suite. For the IOMeter database, RoboBench write, and RoboBench copy tests, the drives were put in a simulated used state that better exposes long-term performance characteristics. Those tests are all scripted, ensuring an even playing field that gives the drives the same amount of time to recover from the initial used state.

  • We run virtually all our tests three times and report the median of the results. Our sustained IOMeter test is run a second time to verify the results of the first test and additional times only if necessary. The sustained test runs for 30 minutes continuously, so it already samples performance over a long period.

  • Steps have been taken to ensure the CPU’s power-saving features don’t taint any of our results. All of the CPU’s low-power states have been disabled, effectively pegging the frequency at 3.5GHz. Transitioning between power states can affect the performance of storage benchmarks, especially when dealing with short burst transfers.

The test systems’ Windows desktop was set at 1920×1080 at 60Hz. Most of the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.



When we tested the T3 last year, we were wowed by its compact form factor and peppy speeds. Samsung’s Portable SSD T5 is a straightforward upgrade over its predecessor. The drive has made sizeable performance gains while retaining the same svelte footprint. The T5 is an unqualified performance winner in our book, so is it a good value, too?

Samsung Portable SSD T5 500GB

Samsung Portable SSD T5 1TB

August 2017

Newegg was selling the T3 2TB for $750 when we reviewed it. It remains to be seen what retailers will end up charging for the T5, but Samsung is setting the suggested prices at $200 for the 500GB drive and $400 for the 1TB drive. That’s a tad more per gigabyte than the T3 demanded, but between the T5’s noticeable performance improvements and the sorry state of SSD prices, we’re relieved that Samsung didn’t jack up its asking price even more. After all, equivalent 850 EVOs (which came out almost three years ago) are going for $175 and $370 right now, so the portability tax is relatively low.

The T5’s 64-layer V-NAND, miniscule aluminum body, and breakneck speeds (for USB) combine to make it the best portable SSD we’ve yet reviewed. As long as it retails near Samsung’s suggested prices, it will be reasonably affordable, as well. If you’re looking for tiny, durable, and blazing fast external storage, look no further. We can heartily recommend Samsung’s Portable SSD T5.

Comments closed
    • willmore
    • 5 years ago

    A few points.

    First, is it SATA on the M.2 connector? If so, then that’s going to be the same performacne as SATA over mSATA. The only benefit would be that the SSD portion of the device would be a tiny bit smaller, but these don’t seem to be limited in size by the SSD portion anyway, so I don’t think that’s an issue.

    If you meant to use PCI-E on that M.2 to a SATA controller on the M.2 card, then the performance could be better, but we’re back to the PCI-E power issue I mentioned.

    • Chrispy_
    • 5 years ago

    M.2 doesn’t equal NVMe.

    This is a common mistake that a lot of poeple make, but SATA is [i<]by far[/i<] the most common variety of M.2 drive, for two reasons: 1) It's cheaper, so every laptop manufacturer will usually cut corners and use it over NVMe 2) It's more compatible since NVMe support hasn't been around as long as SATA.

    • Chrispy_
    • 5 years ago

    M.2 is just the connector, not the protocol.

    An M.2 version of this would still be using AHCI over SATA like the mSATA version does, only smaller and a more common form factor.

    • juzz86
    • 5 years ago

    Tony, I really enjoyed the review mate.

    They’re a bit expensive for me yet, but this was an excellent piece – thankyou!

    it’s also nice to see a proper USB to M-SATA bridge in there this time!

    • smilingcrow
    • 5 years ago

    I had an 840 EVO which I sold once they got the fix in, on the second attempt I think!
    And the vanilla 840 took forever to get fixed.
    Considering how long it took them to sort the issue I felt a recall was in order so I don’t trust Samsung to test their products properly or do the right thing when things go wrong.
    I took a punt on the T1 1TB mainly due to getting a very good deal and also the convenience factor. Happy so far.

    • willmore
    • 5 years ago

    I would guess it’s the higher power draw of the PCI-E interface. Next step would be a flash controller with native USB3.

    • Chrispy_
    • 5 years ago

    Yeah, mSATA is a dead form factor, that’s what I was getting at.

    Perhaps the mSATA market isn’t quite dead enough that Samsung wants to abandon it, but they can’t justifty making mSATA boards solely for the remaining market. By using up mSATA boards in their own portables, they’re adding enough demand for mSATA that it’s worth keeping the form-factor around for a bit longer.

    • ptsant
    • 5 years ago

    I wonder how reliable are these drives. While I certainly don’t want to go back to the prices of the SLC drives, something about 64-layer NAND makes me a bit wary. Will my data be still there 2 years later? 5 years? 10 years? Will it crash and burn?

    It is certainly nice as a bigger/faster replacement for a USB flash drive and way more reliable than those.

    Also, I’m boycotting Samsung for the 840 EVO bug.

    • derFunkenstein
    • 5 years ago

    Wouldn’t it work with M.2 AHCI drives, though? mSATA seems like a dead form factor. Only thing I can think of is that maybe Samsung has a bunch of mSATA drives (or just mSATA PCBs) laying around.

    • PBCrunch
    • 5 years ago

    I would imagine it has something to do with USB 3.0 UASP offering up high performance and compatibility. I bet UASP doesn’t work with NVMe drives.

    • Chrispy_
    • 5 years ago

    I wonder why Samsung keeps using mSATA SSDs in their T-Series:

    If portability is the name of the game, why not use M.2 2242 form factor? They already churn those out by the bucketload and they’re significantly narrower and shorter, complete with a less bulky connector as well.

    Perhaps the T-series is just Samsung’s attempt to expand their use of mSATA boards enough to justify keeping the mSATA production going at all.

    • smilingcrow
    • 5 years ago

    I have the T1 1TB and whilst it’s an indulgence the tiny form factor, performance and lack of noise make it a keeper. If I hadn’t bought it for £165 a year ago there’s no way I’d pay current prices.

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