USB 3.0 allows external hard drives to realize their performance potential. Each of the three external USB 3.0-based 2.5” disks we're reviewing also excels in some other discipline. We study these specialties up close: speed, capacity, and durability.
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.
- Outside The Box: Three USB 3.0-Based Hard Drives
- Adata DashDrive Durable HD710 (750 GB)
- Hitachi Touro Mobile Pro (750 GB, HTOLMNA7501BBB)
- Western Digital My Passport (2 TB, WDBY8L0020BBK)
- Technical Data And Test Configuration
- Benchmark Results: Throughput And Interface Bandwidth
- Benchmark Results: Access Time And I/O Performance
- Benchmark Results: Real-World Copying
- Picking The Right External 2.5" Hard Drive

The theoretical bandwidth of USB 3.0 is roughly 625 MB/s, but this speed is rarely achieved -- even with the fastest hardware -- because the bus relies on a protocol for transferring data which is poorly optimized and eats up a chunk of the bandwidth.
The theoretical bandwidth of USB 3.0 is roughly 625 MB/s, but this speed is rarely achieved -- even with the fastest hardware -- because the bus relies on a protocol for transferring data which is poorly optimized and eats up a chunk of the bandwidth.
I get like 70~140 MB/s (copying from WD my passport 1TB to my WD HDD (7200rpm black))
and I get 30~40 MB/s copying from USB 2 WD my book 2TB to ^^^^^^^^^^^^^^^
USB 3 is more than twice as fast as USB 2.
Yeah but you're still limited to both the source and destination drive's read/write speed. So when copying from a HDD to an HDD, you're unlikely to exceed 140 MBps.
If you're copying from a SATA 3 SSD to a USB 3.0 SSD, then yes, you could see much faster speeds.
USB 3.0 in most instances isn't ready for prime time for external HDD's, and without UASP the queuing is too slow; UASP solves this problem. Otherwise without UASP IMO use eSATA or a backup internal SATA HDD.
More info see TH article June 20th, 2012 - http://www.tomshardware.com/reviews/usb-3-uas-turbo,3215.html
Note: The Hitachi Touro fails (BSOD) in Windows 8.
Yes.
that 1tb is in a better case than the 2tb
what i have noticed with usb 3 is that, yes while its theoretical max is higher than current hdd and ssds should achieve, the fact of the matter is they never hit that peak.
thats why im wondering, with an ssd, what is the best we can get usb3 to.
you proved that current normal hdds in a good case do not have a problem in usb 3, and for that i thank you.
Well Yes and No... It really depends on your application, eSata may be faster, but USB is still more usable/universal.
If you're planning on using the drive for back up purposes eSata and know all the devices you are going to use it with support eSata, then it is probably the better solution.
If you want it for mobility purposes, transferring files to various destinations, USB is more reliable. First these usb3 drives are self powered, meaning no AC adapters to worry about, the PC provides the power, also since its backwards compatible with usb2.0 100% of the devices you want to plug into will work, eSata is great but its not nearly as widely adopted as usb... I'd rather transfer my files slowly at usb2.0 speeds to my destination system, than not at all due to a lack of eSata ports.
from what i understand.
a usb3 case that takes full advantage of the harddive is hard to find, much less cheap
how ever a esata case can be found for under 30$
so really it comes to how you are going to use the hdd...
personally i want to take all moving parts out of my computer besides fans, so i could go with esata and be happy, but if you want more or less a guarentee that you will be able to hood that drive up to almost anything you can think of, even a bad usb3 case would be better.
You probably have USB 2.0 devices, paired with a motherboard with a not really good (or without proper drivers) Chipset. Most USB 2 can reach up to 30 to 40, as stated earlier, but this is with higher tier chipsets.
even when i plug the hdd into my usb3 slot
anyone can help me?