Even in this day and age of blazing-fast SSDs and inexpensive Blu-ray burners, external hard disks remain the top choice for blending mobility, capacity, and performance. There is no way for conventional magnetic storage to outperform solid-state storage, and optical storage is just so much less convenient. So, yeah, mobile hard drives are a lot slower than SSDs and, in many ways, they're less robust than Blu-ray discs. However, they do offer other advantages like comparatively high capacities at lower and the built-in compatibility associated with USB. Just plug them into any semi-modern PC or Mac, and their respective operating systems automatically load the requisite drivers.
External 2.5" disks are perceived as small and light-weight, though they give up a lot of space compared to 3.5" models. But smaller drives offer several advantages that help even the playing field a bit. Aside from their pocket-friendly size, many 2.5" drives are able to draw all of the power they need through the USB interface. Say farewell to bulky wall warts and black bricks.
Fortunately, 2.5" drives have evolved tremendously, picking up capacity along the way. They can't yet match the multiple terabytes crammed into 3.5" disks. However, one of the models we're reviewing packs in an enormous 2 TB, which is half of the capacity of the largest 3.5" external drive. Moreover, it does this in less than one-quarter of the 3.5" solution's volume. The other two contenders on our bench both weigh in with 750 GB, which is a little more typical in the 2.5" space.
Where 2.5" drives really do fall short, however, are in performance benchmarks. Even complemented by identical USB 3.0 controllers, 2.5” disks are slower than the 3.5" options out there due to the physics of angular velocity and how it affects the amount of data passing under the heads. But as we've shown in the past, the fastest 2.5" models achieve up to 80 MB/s or so, serving up enough sequential throughput for everyday use. Not all drives are created equal, though, and for good reason: the road warrior who needs to transport lots of data needs a storage device that behaves differently than a network admin's super-fast backup target.
We rounded up three external drives geared toward different types of users, and we want to know how they perform both in synthetic and real-world tests. Adata's DashDrive Durable HD710, Hitachi's Touro Mobile Pro, and Western Digital's My Passport are all on our test bed and ready to go.
Adata's USB 3.0-based DashDrive Durable HD710 is available in capacities of 500 GB, 750 GB, and 1 TB. You can find the external case highlighted by yellow, blue, or black, and there's no price difference between the colors. We just so happened to test a blue 750 GB model, which sells for just over $100 on Amazon. We liked that the drive's USB 3.0 cable is integrated, and thus cannot be forgotten or, worse, lost.
The DashDrive Durable HD710 is ruggedized, and Adata isn’t shy about advertising that fact. Its massive case sports diagonally-printed stripes that make us think of highway warning signs. According to its manufacturer, the HD710 conforms to the international standard IEC 529 IPX7, surviving a 30-minute immersion in 1 m (3 ft) of water. It can also survive a drop test, according to MIL-STD-810G 516.5, which is equivalent to a fall from a table to the floor.
Somewhat disappointingly for such a purportedly tough drive, its warranty runs out after a mere three years.
Robustness is what sets the Adata drive apart from the other two products in our story. It's suitable for taxing operating conditions that might render other mechanical devices unusable. Inside, Adata employs a 5400 RPM hard drive, which assures modest (but not particularly noteworthy) performance. Its sequential read and write rates of 77.8 MB/s earn the DashDrive a last-place finish amongst our three test candidates. Then again, that's not too far down the ladder. Western Digital's My Passport achieves a slightly higher result that hovers around 83 MB/s.
In contrast to its competitors, Adata's DashDrive Durable HD710 does not come with software. Its bundle is limited to a quick-start guide and the USB 3.0 cable built right into the external enclosure. Two tools, OStoGo and UFDtoGo, can be downloaded from the Adata website. But they're relatively mundane offerings: OStoGo copies the files off of a Windows 7 DVD on the external drive, and then modifies them in such a way that you can install Windows from the HD710. UFDtoGo synchronizes personal data (like email and browser favorites) between a PC and Adata's product.
We previously tested the 500 GB Hitachi Touro Mobile Pro, and it proved to be one of the fastest 2.5” drives we've seen. In fact, it claimed a ranking in the top third of our USB 3.0 Storage Charts. The 750 GB version (HTOLMNA7501BBB), which sells for less than $100, is slightly faster still.
The piano black Touro Mobile Pro sports a USB 3.0 interface like its smaller sibling, and it also boasts a 7200 RPM drive inside. But that's where similarities to the 500 GB model end. The 750 GB version is the fastest external 2.5” drive we have ever tested. Its maximum sequential read rate of 125.6 MB/s and its maximum write speed of 125.5 MB/s make it the new speed king, pushing the previous winner, Samsung's S2, down one spot, even though the S2 is still better with small files.
It's also worth noting that, while Samsung's S2 loses out to Hitachi's Touro Mobile Pro in synthetics, it remains faster in real-world metrics, such as the copy test.
Hitachi's drive is positioned as a professional product for backing up data. Although it can be used to save information from the cloud, the Touro Mobile Pro is also capable of putting data into the cloud through a bundled application called Hitachi Backup. The software includes 3 GB of online storage space, and is upgradeable to 250 GB for $49 per year. The box also contains a quick-start guide and a USB 3.0 cable.
Hitachi Backup may not be feature-rich, but this Flash-based application is easy to use. By default, it copies the logged-in user's data to the external drive or the cloud either at pre-defined times or on demand. You can specify different folders for the two backup targets, and also define the number of revisions to keep. The latest backup is available in a folder named “Current,” and older backups are found in “Archived.” With a slider, you can specify the bandwidth usage of the cloud backup function as “Low,” “Medium,” or “High”.
Adata's drive is the toughest one, Hitachi's is the fastest, and Western Digital's submission turned out to be the largest, setting a new capacity record for external 2.5” drives with 2 TB of space.
In order to fit 2 TB on a 2.5” drive, Western Digital's disk consists of four 500 GB platters. This leads to a slightly thicker case (0.83”). But, all things considered, the chassis is still smaller than the ruggedized Adata drive, and only marginally heavier, weighing in at 0.5 lbs. Like its storage capacity, the My Passport's price is hefty at $200. When you divide capacity into cost, though, this model is actually pretty comparable to the competition.
If the 2 TB model is too rich for your blood, Western Digital also sells 500 GB, 750 GB, and 1 TB versions of the My Passport.
Western Digital's drive features a 5400 RPM disk drive able to achieve maximum sequential read rates of 83.5 MB/s and maximum sequential writes as high as 83.3 MB/s. That's slightly faster than Adata's DashDrive Durable HD710, but it can't come close to Hitachi's Touro Mobile Pro.
The bundled software, SmartWare 1.5.4.5, is an all-around tool for backing up, restoring, and erasing data. It features a timer function that can turn off the drive, along with a diagnostic utility. Each software feature is accessed via a separate tab, aiding ease of use.
Although auditioning the software didn't reveal any amazing innovations, there is a handful of features we liked. For instance, SmartWare can execute a backup after an idle timer triggers the action, which should minimize the impact on productivity after someone steps away from their machine. The backup tool supports versioning; it keeps a user-configurable number of older file versions.
Another integrated tool, WD Security, allows you to enter a drive password. The My Passport only appears as an accessible drive after the password is entered.
Technical Data
| Make | Adata | Hitachi | Western Digital |
|---|---|---|---|
| Product Family | DashDrive Durable HD710 | Touro Mobile Pro | My Passport |
| Model Number | AHD710-750GU3-CBL | HTOLMNA7501BBB | WDBY8L0020BBK |
| Form Factor | 2.5" | 2.5" | 2.5" |
| Capacity | 750 GB | 750 GB | 2 TB |
| Platters | 2 | 2 | 4 |
| Rotational Speed | 5400 RPM | 7200 RPM | 5400 RPM |
| Other Capacities | 500 GB, 1 TB | 500 GB | 500 GB, 750 GB, 1 TB |
| Interface | USB 3.0 | USB 3.0 | USB 3.0 |
| Dimensions (W x H x D) | 3.9" x 0.8" x 5.2" | 3.15" x 0.6" x 5.0" | 3.2" x 0.8" x 4.4" |
| Weight | 0.48 lbs. | 0.34 lbs | 0.5 lbs |
| Warranty | Three Years | Two Years | Two Years |
Test Configuration
| System Hardware | |
|---|---|
| Hardware | Details |
| CPU | Intel Core i7-920 (Nehalem) 45 nm, 2.66 GHz, 8 MB L2 Cache |
| Motherboard (LGA 1366) | Supermicro X8SAX, Revision: 1.0, Chipset Intel X58 Express + ICH10R, BIOS: 1.0B |
| Memory | 3 x 1 GB DDR3-1333 Corsair CM3X1024-1333C9DHX |
| Hard Disk | Seagate NL35 400 GB, ST3400832NS, 7200 RPM, SATA 1.5Gb/s, 8 MB Cache |
| Storage Controller | eSATA: On-Board eSATA (ICH10R) USB 2.0: On-Board USB 2.0 (ICH10R) USB 3.0: NEC D720200F1 (Gigabyte GA-USB3.0) |
| Power Supply | OCZ EliteXstream 800 W, OCZ800EXS-EU |
| Benchmarks | |
| Performance Measurements | h2benchw 3.13 |
| I/O Performance | IOMeter 2008.08.18 Fileserver Benchmark Web server Benchmark Database Benchmark Workstation Benchmark Streaming Reads and Writes |
| System-Software & Drivers | |
| Operating System | Windows 7 Ultimate |
Driven by its 7200 RPM disk, Hitachi's Touro Mobile Pro achieves a throughput of more than 125 MB/s, which earns it a top spot in this largely theoretical measurement. The previous speed king, Samsung's S2, is pushed to second place.
The other two new drives, Western Digital's My Passport and Adata's DashDrive Durable HD710, sport 5400 RPM disks and end up finishing fairly close to each other in the performance chart by pushing 83 MB/s and 78 MB/s, respectively.


The Hitachi Touro Mobile Pro is the strongest contender in this line-up when it comes to streaming reads and writes, though Iometer is less forgiving than h2benchw. The Adata DashDrive Durable HD710 and the Western Digital My Passport still cannot compare, though, as they're similarly beaten-up by Iometer.


Among today's three contenders, access times vary by only seven milliseconds. That's small enough to not affect the test results by much.


There is a notable performance difference between the Hitachi drive, on one hand, and the Adata and Western Digital drives, on the other. The Iometer benchmarks demonstrate this. In the file server and Web server workloads, Hitachi's Touro Mobile Pro outclasses its competition. Adata's DashDrive Durable HD710 and Western Digital's My Passport occupy a lower performance echelon, finishing close together and challenging each other for second place among our three candidates.
Despite the Touro's strong showing in these two charts, however, the results are only marginally relevant. External USB 3.0-based disk drives aren't designed for I/O-heavy tasks. So, it's less likely that you'd replicate these numbers than the sequential benchmark figures on the previous page.
Real-world results would be even better. On the next page, we'll dig into what these drives are really meant to do: copying files.


JPEG Images
We're really able to see the benefit of adopting USB 3.0-connected drives when it comes to transferring large files. But the performance picture isn't perfect.
Although Hitachi's 750 GB Touro Mobile Pro is a strong performer in the read test, it gets beaten by Western Digital's 2 TB My Passport for the first time in our round-up. It also succumbs to Samsung's S2 and a 500 GB version of itself. It also loses to the Samsung S2 in our write test.
As a test control, we have a couple of USB 2.0-based drives at the bottom of the chart. Their performance is very similar because they're being constrained by the bus' maximum throughput. Truly, USB 3.0 is instrumental in popping the cork on external storage performance.


MP3 Files
When we start moving compressed MP3 audio, the results appear largely similar. Western Digital's My Passport scores another win over Hitachi's Touro Mobile Pro, which takes second place in read performance. Hitachi reasserts itself in the write workload, though not by as large of a margin as the streaming Iometer numbers would have indicated.



The real star of the show today is USB 3.0, which allows the Adata DashDrive Durable HD710, Hitachi Touro Mobile Pro, and Western Digital My Passport to demonstrate their respective advantages, while allowing us to pinpoint their weaknesses without interference from a USB bottleneck. Technically, you could pick any one of these three external disks and be satisfied with it. However, each has specific strengths that endear it to a particular type of customer.
The Fastest: We cannot hand Hitachi's Touro Mobile Pro an unconditional victory when it comes to performance. It loses out to Western Digital's My Passport in the real-world read tasks we'd expect these drives to be tasked with. Moreover, Samsung's S2 demonstrates more consistently-good results overall.
Hitachi does particularly well in our synthetic metrics, where it takes a number of first-place finishes. Sporting a maximum sequential read/write rate of 125 MB/s in h2benchw, you'd expect the Touro Mobile Pro to decimate its competition in picture and music file transfers. Although it is the fastest drive of the three we tested, its advantage shrinks quite a bit. In this round-up, at least, Hitachi scores a victory, though we'd hardly call it commanding.
The Toughest: If you're shopping for an external drive able to take a beating, the number of viable options drops precipitously. Fortunately, Adata's DashDrive Durable HD710 does qualify. This ruggedized option is able to drop from a tablet to the floor or spend half an hour at the bottom of a garden fountain without compromising your data. In spite of its specially-designed chassis, the DashDrive Durable HD710 is only slightly larger than non-ruggedized drives, and barely heavier, weighing in at 0.5 lbs. Its performance is average, making it respectably quick. Even though we would have liked to see a greater-than three-year warranty on this particular model, Adata can at least rest easy knowing it offers one more year of coverage than either Hitachi or Western Digital.
The Largest: Diminutive physical dimensions do not give away the fact that Western Digital's My Passport crams in an impressive 2 TB of capacity, representing a new record for 2.5” drives. If you need to maximize this ever-important variable, the My Passport is a winner. Just be ready to pay about $200 for the drive. That's only 10 cents per gigabyte, which isn't bad overall.
The good news is that Western Digital doesn't necessarily compromise performance in its aim to serve up lots of storage space. Its 5400 RPM drive is able to outmaneuver Hitachi's 7200 RPM model in our real-world read tests. It finishes further down the stack in our write tests, and is more similar to Adata's DashDrive Durable HD710 in the synthetics. You'd likely have a hard time telling the difference during day-to-day use, though.
So, Who Wins?
Each of these three drives satisfies a purpose. And, in a way, none of them directly compete against the others as a result of their different balances between performance, capacity, and durability. As a result, we'd have an equally difficult time declaring a winner as a loser; each serves its purpose well in its specialty. The key is knowing what you're looking for in a drive before you sit down to buy one. Perhaps our comparison will help guide such a purchasing decision.



















