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WD Black 2 Dual Drive review: Capacious and affordable SSD-based storage

WD releases a first-of-its-kind standard laptop internal storage drive that comes with a 120GB SSD and 1TB HDD on the inside. Here's CNET's full review of it.

Dong Ngo SF Labs Manager, Editor / Reviews
CNET editor Dong Ngo has been involved with technology since 2000, starting with testing gadgets and writing code for CNET Labs' benchmarks. He now manages CNET San Francisco Labs, reviews 3D printers, networking/storage devices, and also writes about other topics from online security to new gadgets and how technology impacts the life of people around the world.
Dong Ngo
7 min read

For the first time ever, laptop users can now have a dual-drive setup on their computers. All thanks to the WD Black 2 Dual Drive.


WD Black 2 Dual Drive

The Good

The <b>WD Black 2 Dual Drive</b> offers fast SSD-based performance while providing 1.2TB of total storage space. The drive can be used with both laptops and desktops and includes a generous five-year warranty, useful software, and a handy USB-to-SATA connector.

The Bad

There's no support for RAID, and you can't blend the two included drives into one single partition; compared with high-end SSDs, the performance is a little disappointing. At the time of the review, the drive only works with Windows.

The Bottom Line

Fast, user-friendly, and affordable, the WD Black 2 Dual Drive is an easy recommendation as a replacement drive for any standard laptop or desktop computer.

The new internal storage device has a solid-state drive (SSD) and a regular hard drive (HDD) inside the standard laptop design. Prior to it you would have needed two separate drives to achieve the same effect, and could only do that with a desktop computer.

The reason this is significant is because this drive has fast performance and 1.2TB of storage space, without the premium cost of an SSD of the same capacity. And for this purpose, at the cost of $300, the WD Black 2 Dual Drive delivers.

In my testing, the Black 2 was easy to install and offered the equivalent performance of an entry-level 120GB SSD. Unfortunately, the drive doesn't offer a way to blend its two drives into a single partition without losing performance, which is why it's not a hybrid drive.

In all, the WD Black 2 Dual Drive is an affordable dual-drive solution with ample space for both laptops and desktops, and is an excellent choice as a replacement drive. For more options on great internal drives, check out those on this list.

WD Black 2 Dual Drive
The WD Black 2 Dual Drive takes the shape of a standard laptop SATA hard drive. Dong Ngo/CNET

Standard design, yet totally original
From the look, the WD Black 2 Dual Drive is just like any standard laptop internal drive. The drive measures 2.5 inches diagonally, is 9.5mm thick, and supports SATA 3 (6Gbps) standard. This means the drive will work with any standard laptop or desktop, but not ultrabooks which generally require thinner drives. You can install it in a computer just like you do any regular laptop hard drive.

On the inside, however, it's totally unprecedented: the drive comes with a 120GB SSD and a 1TB HDD. These two drives share the single SATA connector.

In many ways, the Black 2 is WD's answer to the solid-state hybrid drives (SSHD) from Seagate or Toshiba, which combine both SSD and HDD into one physical drive to offer an SSD-like performance boost. WD's solution offers real SSD performance, however.

On the inside, the Black 2 Dual Drive comes with one 120GB solid-state drive and one 1TB hard drive.
On the inside, the Black 2 Dual Drive comes with one 120GB solid-state drive and one 1TB hard drive. Dong Ngo/CNET

Not a hybrid drive
The reason the WD Black 2 is not an SSHD is because the two drives on the inside are not meant to be merged. They remain two separate volumes, just as you would use two physical drives in a system. At least this is the way WD recommends it's used.

In my quick trial, I was able to merge the two into one single partition of 1.2TB. However, according to WD, in this case the system doesn't know where the SSD part begins and ends, and therefore it is not optimized for performance. In other words, if you wanted to, you could use the WD Black 2 Dual as a hybrid drive, but there's no benefit to this, at least for now. In the case of Seagate's SSHD, the drive comes with built-in algorithm to automatically allocate hot (frequently accessed) data to the SSD part.

With WD's Black 2 Dual Drive, you will see real SSD performance immediately, whereas with the Seagate's SSHD the boost in performance is only realized gradually, and the drive is never really as fast as a real SSD.

The WD Black 2 installation software will unlock the HDD portion of the WD Black 2 Dual Drive and format it into a new partition for the user.
The WD Black 2 installation software will unlock the HDD portion of the WD Black 2 Dual Drive and format it into a new partition for the user. Dong Ngo/CNET

Two-step installation, no RAID support
Out of the box, when plugged into a computer only the Black 2's SSD drive is recognized, and it looks as though it's a 120GB SSD. You can install Windows on this drive (the Black 2 only works with Windows for now, but Mac support is coming soon), or clone an existing system onto it. In the latter case, you'll find the included USB-to-SATA transfer cable and Acronis drive clone and backup software very helpful; just make sure the system's old drive has less than 120GB of data on it. (If you need help cloning your systemcheck out this how-to post.)

Once your computer is up and running with the 120GB portion hosting the operating system, you need to install the Black 2 installer software, which reveals the 1TB HDD and formats it into a separate partition. Now, after a restart, your system has two drives, with the OS and applications residing on the SSD and the HDD being the secondary drive for extra storage space.

Note that the installer software's only job is to unlock and format the HDD portion. After that you can safely remove it from your computer, and if you don't, it doesn't run each time your computer starts. I believe WD purposefully locked the 1TB hard drive out of the box so you won't mistakenly install an operating system on it -- the SSD is supposed to host the OS and programs to offer the best performance.

As you might imagine from this two-step setup, the Black 2 Dual Drive is not designed to be used in RAID configurations.

The drive comes in a retail package that includes a handy USB 3.0-to-SATA cable and helpful free downloadable system cloning software.
The drive comes in a retail package that includes a handy USB 3.0-to-SATA cable and helpful free downloadable system cloning software. Dong Ngo/CNET

Cost per gigabyte
At $300 for 1.2TB total, the Black 2 Dual Drive costs 25 cents per gigabyte. Compared with a regular laptop drive, which generally goes for somewhere between 7 cents and 15 cents per gigabyte, the new WD drive is quite expensive. But compared with real SSDs, which cost up to $1 per gigabyte, it's a steal.

At around 11 cents per gigabyte, most SSHDs are more affordable than the Black 2, but none can offer even close to its performance. In all, I find the Black2 Dual Drive competitively priced; you can expect its street price to go even lower.

If you set up the WD Black 2 Dual Drive correctly, its performance is that of the 120GB SSD; the 1TB HDD is just for storage data and plays no role in the system's performance. Accordingly, in my testing the drive offered the performance of a typical entry-level 120GB SSD.

Compared with a regular hard drive, the Black 2 helped significantly boost the performance of the test machine, making it boot up much faster, taking about 13 seconds. The system also resumed from sleep mode almost instantly and applications launched much faster.

CNET Labs' data transfer scores
(Longer bars indicate better performance)
As Secondary Drive (Read Only)
As Secondary Drive (Write only)
As OS Drive (Read and Write)
OCZ Vector
Seagate 600 SSD
Plextor M5 Pro Xtreme
Transcend SSD720
WD Black 2 Dual Drive
SanDisk Extreme II
OCZ Vector 150
Samsung 840 Evo (Rapid)
Samsung 840 Evo
Seagate Laptop Thin SSHD

In sequential copy tests, the drive offered a sustained speed of some 115MBps for writing, which was the slowest among the SSDs I've reviewed, but much faster compared with regular hard drives. Note that all SSDs I've reviewed were at least 240GB or larger, and, in the world of SSDs, a larger capacity generally means faster performance. In writing, the drive did much better with aq score of 228MBps, though that was still just average on the chart. In tests where it performed both writing and reading at the same time, the drive registered 175MBps, below the average of other SSDs.

In PC Mark 8 benchmark, where the entire system was tested as a whole, the drive performed on par with other SSDs.

PC Mark 8 Scores
(Longer bars indicate better performance)
Storage Score
Work Score
Home Score
Samsung 840 Evo
OCZ Vector
OCZ Vector 150
Plextor M5 Pro Xtreme
SanDisk Extreme II
Seagate 600 SSD
WD Black 2 Dual Drive
Transcend SSD720

Offering the performance of an entry-level SSD, 1.2TB of total storage space, and a $300 price-tag, the WD Black 2 Dual Drive is the most affordable and largest capacity SSD-based storage solution to date. For example, the Samsung 840 Evo, which is one of the least expensive SSDs on the market, cost some $330 for just 500GB, or the recently reviewed OCZ Vector 150, $260 for just 240GB. While the Dual Drive is not a conventional SSD throughout, the difference is minimal thanks to the use of a real and dedicated SSD as the main drive to host the operating system and software.

That said, with a top five-year warranty to back it up, the WD Black 2 Dual Drive deserves one of the top spots on my list of recommendations for replacement internal drives if you have an older computer that still uses a hard drive as its main storage, be it a desktop or laptop. When support for Mac is available, the drive will be like your very own Fusion drive for your older Mac.


WD Black 2 Dual Drive

Score Breakdown

Setup 9Features 8Performance 8Support 9