By David Ramsey

Manufacturer: Transcend Information, Inc.
Product Name: Portable Solid State Drive
Part Number: ESD400
UPC: 0760557828471
Price As Tested: $59.99 128GB / $94.99 256GB / $184.99 512GB / $364.95 1TB

Full Disclosure: Transcend Information Inc. provided the product sample used in this article.

Transcend Information Inc. was founded in Taiwan in 1988, and the company prides itself on “organizing your digital life.” Their new ESD400 series of external USB SSDs is their entry into the market for portable, USB-powered SSDs that aims to replace the mature 2.5″ hard drive that’s dominated the small external drive market for years. With sequential read and write speeds both spec’d in the range of 400 megabytes per second, the rated performance of this drive is vastly better than any spinning hard drive. Benchmark Reviews checks out the 256GB version of the ESD400 in this review.

Capacity	256 GB
Interface	USB 3.0 (5gbs)
Form Factor	Custom, 92mm x 62mm x 10.5mm
NAND	MLC NAND Flash
TRIM	No
NCQ?	No
Max. Read	Up to 410 MB/sec
Max. Write	Up to 380 MB/sec
Warranty	3 years

No matter how fast your processor, memory, or video card is, your computer will still be limited by its slowest component: the hard disk. While hard disk speed has improved tremendously since the “early days”, with large caches and 10,000RPM spindle speeds, even the fastest hard disk’s performance is glacial compared to the rest of the computer. The situation only gets worse with modern pre-emptive multitasking operating systems, where dozens of threads are running simultaneously and competing for your disk’s limited response time and bandwidth.

Consider: the average time to move a high-performance hard disk’s read/write head to a new track will be less than 10ms, which seems pretty fast. But your CPU is galloping along at billions of cycles per second, and will spend a significant amount of its time just waiting for the hard disk to fulfill its last request. Hard disk performance has plateaued in the last few years, running up against the physical limitations of spindle speeds, magnetic media density, and head servomotor performance. At the end of the day, disks are limited by the fact that they’re comprised of physical, moving parts.

With no moving parts, Solid State Drive technology removes this bottleneck. The difference an SSD makes to operational response times and program speeds is dramatic: while a faster video card makes your games faster, and a faster processor makes compute-bound tasks faster, Solid State Drive technology makes your entire system faster, improving initial response times by more than 450x (45,000%) for applications and Operating System software, when compared to their mechanical HDD counterparts. The biggest mistake PC hardware enthusiasts make with regard to SSD technology is grading them based on bandwidth speed alone. File transfer speeds are important, but only so long as the operational I/O performance can sustain that bandwidth under load.

As we’ve explained in our SSD Benchmark Tests: SATA IDE vs AHCI Mode guide, Solid State Drive performance revolves around two dynamics: bandwidth speed (MB/s) and operational performance I/O per second (IOPS). These two metrics work together, but one may be more important than the other. Consider this analogy: bandwidth determines how much cargo a ship can transport in one voyage, and operational IOPS performance is how fast that ship moves. By understanding this and applying it to SSD storage, there is a clear importance set on each variable depending on the task at hand.

For casual users, especially those with laptop or desktop computers that have been upgraded to use an SSD, the naturally quick response time is enough to automatically improve the user experience. Bandwidth speed is important, but only to the extent that operational performance meets the minimum needs of the system. If an SSD has a very high bandwidth speed but a low operational performance, it will take longer to load applications and boot the computer into Windows than if the SSD offered a higher IOPS performance.

Like the Samsung Portable SSD T3, the Transcend ESD400 is much smaller than a typical 2.5″ USB-powered external hard drive. There’s no standard size for external SSDs and the dimensions, while similar to the Samsung, are slightly different.

The case seems to be all plastic, and there’s a subtle diamond patters on the upper surface, along with a Transcend logo.

The back of the case notes that it’s a USB 3.0 SSD and has the capacity in gigabytes.

The rear of the drive has a button that invokes Transcend’s Elite backup software, and a USB 3.0 Micro B connector for power and data.

Accessories include a Quick Start Guide, which instructs you to plug the drive into a USB 3.0 port with the included cable, a USB 3.0 Type A to USB 3.0 Micro B adapter cable, and a slip pouch for transporting the drive,

A hidden indicator light glows and blinks during drive access:

Let’s take a look at the performance of this drive in the next section.

When we test storage devices, the two main metrics to consider are access time and transfer rate. Simply put, access time is the time is takes the storage device to start delivering data once the request has been received, while transfer rate is how fast (megabytes per second) the data comes once the transfer operation begins. With a hard disk, data transfer cannot begin until the disk’s head servo physically moves the read/write head to the correct track, and the rotation of the disk brings the designated sector under the head. Although modern servos are very fast, in the best case you’re still looking at several milliseconds to do this, while an SSD’s access time is always under a millisecond. The disadvantage is even worse if the data isn’t all in a contiguous space on the disk, since the head will have to be repositioned on the fly, leading to more delays.

Early consumer SSDs actually had slower transfer rates than the best hard disks, although their instantaneous access times more than made up for it. The zenith of consumer hard disk performance was probably reached in 2012 with the release of the Western Digital Velociraptor 1 terabyte disk. Spinning at 10,000RPM, this disk could under ideal circumstances (i.e. a synthetic bandwidth test) reach a sequential transfer rate of over 230MB/s. Keep this figure in mind as you read this review.

Early on in our SSD coverage, Benchmark Reviews published an article which detailed Solid State Drive Benchmark Performance Testing. The research and discussion that went into producing that article changed the way we now test SSD products. Our previous perceptions of this technology were lost on one particular difference: the wear leveling algorithm that makes data a moving target. Without conclusive linear bandwidth testing or some other method of total-capacity testing, our previous performance results were rough estimates at best.

Our test results were obtained after each SSD had been prepared using DISKPART or Sanitary Erase tools. As a word of caution, applications such as these offer immediate but temporary restoration of original ‘pristine’ performance levels. In our tests, we discovered that the maximum performance results (charted) would decay as subsequent tests were performed. SSDs attached to TRIM enabled Operating Systems will benefit from continuously refreshed performance, whereas older O/S’s will require a garbage collection (GC) tool to avoid ‘dirty NAND’ performance degradation.

It’s critically important to understand that no software for the Microsoft Windows platform can accurately measure SSD performance in a comparable fashion. Synthetic benchmark tools such as ATTO Disk Benchmark and Iometer are helpful indicators, but should not be considered the ultimate determining factor. That factor should be measured in actual user experience of real-world applications. Benchmark Reviews includes both bandwidth benchmarks and application speed tests to present a conclusive measurement of product performance.

Motherboard: MSI Z170A GAMING M7 Socket LGA 1151
Processor: 4.0 GHz Intel Core i7-6700K Skylake CPU
System Memory: 16GB DDR4 2133MHz
Operating System: Microsoft Windows 10 Pro

The following storage hardware has been used in our benchmark performance testing, and may be included in portions of this article:

AS SSD Benchmark 1.6.4067.34354: Multi-purpose speed and operational performance test
ATTO Disk Benchmark 2.46: Spot-tests static file size chunks for basic I/O bandwidth
CrystalDiskMark 3.0.1a by Crystal Dew World: Sequential speed benchmark spot-tests various file size chunks
Iometer 1.1.0 (built 08-Nov-2010) by Intel Corporation: Tests IOPS performance and I/O response time
Finalwire AIDA64: Disk Benchmark component tests linear read and write bandwidth speeds
Futuremark PCMark Vantage: HDD Benchmark Suite tests real-world drive performance

This article utilizes benchmark software tools to produce operational IOPS performance and bandwidth speed results. Each test was conducted in a specific fashion, and repeated for all products. These test results are not comparable to any other benchmark application, neither on this website or another, regardless of similar IOPS or MB/s terminology in the scores. The test results in this project are only intended to be compared to the other test results conducted in identical fashion for this article.

Note: Our existing library of SSD test results is almost entirely based on internal SSD drives, connected to a SATA 6G port or an m.2 port. The Transcend ESD400 is a portable drive that connects over USB 3.0, and this will be at a performance disadvantage compared to SATA: the raw data transfer rate is slower (5gbs as opposed to 6gbs), and SATA/AHCI support additional performance optimizations not available to USB drives. Although modern external USB drives are far faster than earlier generation internal SSDs, they will never be as fast as the equivalent generation internal SSDs.

Alex Schepeljanski of Alex Intelligent Software develops the free AS SSD Benchmark utility for testing storage devices. The AS SSD Benchmark tests sequential read and write speeds, input/output operational performance, and response times.

AS-SSD Benchmark uses compressed data, so sequential file transfer speeds may be reported lower than with other tools using uncompressed data. For this reason, we will concentrate on the operational IOPS performance in this section.

Beginning with sequential transfer performance, the Transcend ESD400 portable solid state drive produced 430MB/s for sequential reads and a somewhat disappointing 319MB/s for sequential writes. The 4K-64 thread test we concentrate on in this benchmark produced only 134MB/s reads and writes, both score of which are substantially better than those returned by the Samsung T3.

Transcend ESD400 USB SSD Results

The chart below summarizes AS-SSD 64-thread 4KB IOPS performance results among a variety of enthusiast-level SSDs. The ESD400 returns a very low score relative to the internal SSDs that comprise most of the chart, but manages to handily beat the Samsung T3. Bear in mind that no USB-attached drive can hope to do as well as a SATA drive on this test.

In the next section, Benchmark Reviews tests transfer rates using ATTO Disk Benchmark.

The ATTO Disk Benchmark program is free, and offers a comprehensive set of test variables to work with. In terms of disk performance, it measures interface transfer rates at various intervals for a user-specified length and then reports read and write speeds for these spot-tests. There are some minor improvements made to the 2.46 version of the program that allow for test lengths up to 2GB, but all of our benchmarks are conducted with 256MB total length. ATTO Disk Benchmark requires that an active partition be set on the drive being tested. Please consider the results displayed by this benchmark to be basic bandwidth speed performance indicators.

256GB Transcend ESD400 ATTO Benchmark Results

Although the results are much faster than those from an external USB-powered hard drive, the Samsung is still relegated to the very bottom of the chart for this benchmark. However, note that in this benchmark the maximum read speed of 456MB/s exceeds Transcend’s specification of 410MB/s, while the maximum write speed of 341MB/s is slightly less than the 380MB/s spec.

In the next section, Benchmark Reviews tests sequential performance using the CrystalDiskMark 3.0 software tool…

CrystalDiskMark 3.0 is a file transfer and operational bandwidth benchmark tool from Crystal Dew World that offers performance transfer speed results using sequential, 512KB random, and 4KB random samples. For our test results chart below, the 4KB 32-Queue Depth read and write performance was measured using a 1000MB space. CrystalDiskMark requires that an active partition be set on the drive being tested, and all drives are formatted with NTFS on the Intel P67 chipset configured to use AHCI-mode. Benchmark Reviews uses CrystalDiskMark to illustrate operational IOPS performance with multiple threads. In addition to our other tests, this benchmark allows us to determine operational bandwidth under heavy load.

CrystalDiskMark uses compressed data, so sequential file transfer speeds are reported lower than with other tools using uncompressed data. For this reason, we will concentrate on the operational IOPS performance in this section.

CrystalDiskMark 3.0 reports sequential speeds reaching 424.7MB/s reads and 330MB/s writes.

256GB Transcend ESD300 CrystalDiskMarkResults

The chart below summarizes 4K random transfer speeds with a command queue depth of 32. While very slightly slower than the Samsung T3, the ESD400 does outperform the mSATA MyDigitalSSD.

In the next section, we continue our testing using Iometer to measure input/output performance…

Iometer is an I/O subsystem measurement and characterization tool for single and clustered systems. Iometer does for a computer’s I/O subsystem what a dynamometer does for an engine: it measures performance under a controlled load. Iometer was originally developed by the Intel Corporation and formerly known as “Galileo”. Intel has discontinued work on Iometer, and has gifted it to the Open Source Development Lab (OSDL). There is currently a new version of Iometer in beta form, which adds several new test dimensions for SSDs.

Iometer is both a workload generator (that is, it performs I/O operations in order to stress the system) and a measurement tool (that is, it examines and records the performance of its I/O operations and their impact on the system). It can be configured to emulate the disk or network I/O load of any program or benchmark, or can be used to generate entirely synthetic I/O loads. It can generate and measure loads on single or multiple (networked) systems.

To measure random I/O response time as well as total I/O’s per second, Iometer is set to use 4KB file size chunks over a 100% random sequential distribution at a queue depth of 32 outstanding I/O’s per target. The tests are given a 50% read and 50% write distribution. While this pattern may not match traditional ‘server’ or ‘workstation’ profiles, it illustrates a single point of reference relative to our product field.

All of our SSD tests used Iometer 1.1.0 (build 08-Nov-2010) by Intel Corporation to measure IOPS performance. Iometer is configured to use 32 outstanding I/O’s per target and random 50/50 read/write distribution configuration: 4KB 100 Random 50-50 Read and Write.icf. The chart below illustrates combined random read and write IOPS over a 120-second Iometer test phase, where highest I/O total is preferred:

Again, any USB drive will be at a severe disadvantage relative to SATA drives in tests that try to max out IOPS with multiple threads. Still, the ESD400 does turn in a performance about triple that of the Samsung drive.

In our next section, we test linear read and write bandwidth performance and compare the speed of Samsung’s external SSD against several other top storage products using the AIDA64 Disk Benchmark.

Many enthusiasts are familiar with the Finalwire AIDA64 benchmark suite, but very few are aware of the Disk Benchmark tool available inside the program. The AIDA64 Disk Benchmark performs linear read and write bandwidth tests on each drive, and can be configured to use file chunk sizes up to 1MB (which speeds up testing and minimizes jitter in the waveform). Because of the full sector-by-sector nature of linear testing, Benchmark Reviews endorses this method for testing SSD products, as detailed in our Solid State Drive Benchmark Performance Testing article. One of the advantages SSDs have over traditional spinning-platter hard disks is much more consistent bandwidth: hard disk bandwidth drops off as the capacity draws linear read/write speed down into the inner-portion of the disk platter. AIDA64 Disk Benchmark does not require a partition to be present for testing, so all of our benchmarks are completed prior to drive formatting.

Linear disk benchmarks are superior bandwidth speed tools because they scan from the first physical sector to the last. A side affect of many linear write-performance test tools is that the data is erased as it writes to every sector on the drive. Normally this isn’t an issue, but it has been shown that partition table alignment will occasionally play a role in overall SSD performance (HDDs don’t suffer this problem).

We run the AIDA64 linear read and write tests with a 1M block size. Charted above, read performance on the 256GB Samsung external SSD returned average speeds of 417MB/s. The performance is very linear, with none of the larger spikes I’m used to seeing, except for a dramatic dip down to 70MB/s near the end.

AIDA64 linear write-to tests were next…

Again we see a very linear overall performance from this drive (here, as in some of the other benchmarks, the drive is identified as a “StoreJet” for some reason. Perhaps Transcend is OEMing the controller.)

The linear write performance begs comparison to the Samsung T3, which suffered a dramatic throughput drop partway through the test as shown below:

Although the Transcend results look better, check out the average throughput numbers: 311.8MB/s for the Transcend and 318.6 for the Samsung. The Samsung’s dropoff happens about 32% through its 500GB capacity, or at about the 150GB mark, so you’re unlikely to run into it unless you’re writing very large files.

The chart below shows the average linear read and write bandwidth speeds for a cross-section of storage devices tested with AIDA64. The overall performance of the Transcend drive just barely edges out the Samsung T3.

Linear tests are an important tool for comparing bandwidth speed between storage products, serve to highlight the consistent-bandwidth advantages of SSDs, which don’t suffer the performance drop-off that HDDs do as the test proceeds away from the fast outer edge of the disk.

In the next section we use PCMark Vantage to test real-world performance…

PCMark Vantage is an objective hardware performance benchmark tool for PCs running 32- and 64-bit versions of Microsoft Windows 7. PCMark Vantage is well suited for benchmarking any type of Microsoft Windows 7 PC: from multimedia home entertainment systems and laptops, to dedicated workstations and high-end gaming rigs. Benchmark Reviews has decided to use the HDD Test Suite to demonstrate simulated real-world storage drive performance in this article.

PCMark Vantage runs eight different storage benchmarks, each with a specific purpose. Once testing is complete, results are given a PCMark score while and detailed results indicate actual transaction speeds. The Samsung drive turns in better results in this real-world test than it does on the synthetic tests.

256GB Transcend ESD400 Portable SSD PCMark VantageResults

In the overall PCMark Vantage score, the Transcend drive turns in a score about 20% lower than that of the Samsung T3.

In the next section, I’ll look at the backup software included with this drive.

Transcend’s Elite backup utility is available as a free download to purchasers of this drive. Elite provides a basic, scriptable backup feature that can optionally compress and encrypt backups. Both Mac and Windows versions of Elite are available; I used the Windows version for this review.

Elite is task-oriented: you configure one or more backup tasks, and each task can back up a specific set of files to a specific destination (it doesn’t have to be to the Transcend drive), can be set to run periodically or manually, and can optionally be compressed and locked with a password.

The first thing I noticed was that the backup window is not resizeable, nor can the width of the panes be adjusted, leading to visual issues like this when selecting the files to back up. You can scroll the selection pane horizontally, but it’s a pain. Also, note that the window has no close box; you must use the alt-F4 combination to close it.

Next I noticed that when you’re taking to select the destination, the window only shows drive letters, and not volume names. In this particular example my Transcend drive was “G:”, but it would be much more useful to show volume names…

Once the backup process start, the progress window appears. Confusingly, it’s titled “Confirm Selection”, even though there’s nothing for you to confirm at this point. The type of backup is shown as an icon; I have no idea what the icon represents. A file backup maybe? It does show the available space on the destination volume and the size of the files you’re preparing to back up. The progress bar at the bottom of the window will keep you informed.

In my case, an 81 gigabyte backup took just under 17 minutes.

While the Elite software is both free and functional, its user interface is poor; depending on your needs, you’ll probably want something more sophisticated. It doesn’t even install as a normal Windows application– the .EXE file and its support files are installed in an obscure temp directory under Appdata->Roaming, and you can’t uninstall it using the standard Windows facilities. All in all, it seems a half-hearted effort, at least on the Windows side of things.

In the last section I’ll present my final thoughts and conclusion for the Transcend ESD400 USB SSD drive.

IMPORTANT: Although the rating and final score mentioned in this conclusion are made to be as objective as possible, please be advised that every author perceives these factors differently at various points in time. While we each do our best to ensure that all aspects of the product are considered, there are often times unforeseen market conditions and manufacturer changes which occur after publication that could render our rating obsolete. Please do not base any purchase solely on our conclusion, as it represents our product rating specifically for the product tested which may differ from future versions.

Laptop computers started outselling desktop computers over a decade ago, and this swiftly led to the creation and eventual commoditization of the ubiquitous USB-powered external drive for backup and data transfer. However, these drives were virtually always based on slow, 5,400-RPM 2.5″ mechanisms, which limited performance, especially as laptop capacities grew. Now we have the dawn of the “external SSD”. The Transcend ESD400 is the third external drive I’ve tested recently– the other two being the Samsung T3 and the La Cie Porsche Design drive.

Like the Samsung T3, the Transcend ESD400 uses UASP (USB Attached SCSI Protocol) to maximize its performance. It’s much faster than any mechanical hard drive, and that translates into less time for your backups and file transfers. While the Transcend and Samsung traded places in a few of the benchmarks, overall the performance of the MLC Transcend and TLC Samsung are very similar. The biggest difference in overall performance shows up in the PCMark Vantage test, where the Samsung drive posts a score about 25% better.

While the performance of the Transcend is similar to that of the Samsung, it enjoys a significant price advantage, especially in the 500GB-and-up capacities, as of the time of this writing. There are other considerations– Samsung offers a 2TB version, while Transcend does not; and Samsung’s security software, which allows you to encrypt and password-protect the drive, is arguably more useful than Transcend’s rather uninspiring backup software. Also, the sleek aluminum enclosure of the T3 makes the ESD400’s diamond-patterned black plastic look a little déclassé.

And keep in mind that with either external SSD, you’ll be paying a substantial premium for that solid-state performance: for the price of either drive’s 1TB version, you could buy the 8TB version of the La Cie Porsche Design Desktop drive. And it charges your USB-C laptop, too.

So who’s the intended market? People who need fast backups, or people who don’t want to wait for gigabytes of files to copy? Perhaps both, or perhaps people who just hate spinning hard drives on principle and want something better. OK, that last one’s a stretch, but still: external SSDs are kinda cool.

My only complaint about this drive is the backup software: while functional, its user interface quirks and non-standard Windows installation leave me cold.

Transcend has the ESD400 external SSD 128GB at $59.99, 256GB at $94.99, 512TB at $184.99, and 1TB at $364.95 capacities. These prices all undercut Samsung’s as of the time of this writing, so unless the latter’s security software is a real advantage for you, the Transcend looks like a better buy.

+ Outstanding performance for an external USB-powered drive
+ Very small and light, high impact resistance
+ Less expensive than the competition…for now

– Very expensive compared to traditional external drives
– Lackluster backup utility

Performance: 9.00
Appearance: 8.00
Construction: 9.25
Functionality: 8.75
Value: 9.00

Quality Recognition: Benchmark Reviews Silver Tachometer Award.

COMMENT QUESTION: Which brand of SSD do you trust most?

By David Ramsey

Transcend ESD400 USB SSD Results

256GB Transcend ESD400 ATTO Benchmark Results

256GB Transcend ESD300 CrystalDiskMarkResults

256GB Transcend ESD400 Portable SSD PCMark VantageResults

Quality Recognition: Benchmark Reviews Silver Tachometer Award.

By David Ramsey

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