Review Index:

Western Digital Black2 Dual Drive Full Review - 120GB SSD + 1TB HDD in a single 2.5" package

Subject: Storage
Manufacturer: Western Digital

Setup and Configuration

This may go a bit far on the tech talk but bare with me. Here's how the installation goes:

Out of the box, the Black2 appears as *only* a 120GB SSD. The HDD is there, but not visible to the host system. Here's what it looks like when connected to another system:

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There is a good reason for this. What you want to happen is to either clone or install your OS fresh to the SSD portion. The best way to prevent the Windows installer or cloning software from partitioning into the HDD space is to simply make that space inaccessible during that portion of the setup. Once the OS is installed and you're booted up on the SSD portion of the Black2, you download and install the driver package from WD:

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This is a very simple installer that leaves almost no footprint on the host system. Contrary to what you may think, there is no specific or special storage driver that allows access to the HDD portion. During install, the 'driver' instructs the Black2 to open up the additional space, which it does by tacking the HDD space onto the end of the SSD space. After a reboot (if necessary), the software kicks back in and partitions the HDD space for you. The end result looks like this (seen connected to a test system with its own OS):

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Now I know what you're thinking. You're probably wondering what happens if, say, your OS gets stuck in a blue screen loop, or gets infected with a virus. How can you access the 1TB of space without being able to boot the OS? The answer to that is simpler than you think. The software is not really a 'driver'. Once it's been installed and 'unlocks' the 1TB appended onto the SSD, it stays there. You could remove the Black2 from the installed system and connect it to a completely different system (via SATA, USB, whatever), and the full 1.1TB drive will appear, just as it did in the above pic. This applies even if the system you connected it to has never seen the Black2 driver software. Basically the unlock / driver install process is only there to ensure the HDD space is untouced during initial install and that the second HDD partition is placed correctly.

WD has also considered the above scenarios in the design of their software installer. If, say, you needed to reinstall Windows for whatever reason. So long as you don't touch the HDD partition, you can safely reformat and reinstall in the SSD space. The HDD partition will persist. Once in your freshly installed Windows you may choose to reinstall the Black2 software, and during that process it will gracefully erorr out at the end, where it would normally create the HDD partition (as it's already there).

If you inadvertently delete the HDD partition, simply uninstall the software (it requires the HDD partition removed before it will proceed regardless), and then reinstall it to re-create the partition. I highly recommend letting the software do this as in my testing it creates that partition at a slightly different offset than Windows would by default. Operating on a Windows-created partition caused odd stutters and hiccups, and I suspect that was due to the beginning of that partition crossing over the SSD/HDD boundary. As a final note, the uninstallation process also re-shrinks the addressible space to that of the SSD, priming it for a fresh OS install without the worry of making the partition too large and crossing into the HDD address space.

Testing Complications

Given that the HDD portion is tacked onto the SSD portion and can not be accessed directly, benches run on the combined drives act, well, weird. See for yourself:

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Benches result in a combination of both units. Prior to installing the software, the Black2 can be tested like any other SSD, but testing the HDD portion means you're limited to file-based benches or ones that can test specific LBA ranges.

November 25, 2013 | 08:29 AM - Posted by Robert

The only thing that would make this a perfect option for me is if the 1TB drive were 7200RPM or faster. Perhaps they will come out with one.

November 25, 2013 | 08:57 AM - Posted by Allyn Malventano

If you're using the 1TB for bulk storage, accessed sequentially, the 7200 RPM drive isn't going to get you much more of an advantage. The 1TB may be 5400 RPM, but it hits 140 MB/sec (at the start of the drive space) without issue.

November 25, 2013 | 08:44 PM - Posted by danwat1234 (not verified)

Instead of a 7200RPM drive I would like to see the mechanical drive having 16GB of flash memory itself, so it'll be a hybrid drive, along with the 120GB SSD.

My only concern with the device is that the controller is kind of unstable if you try to intensively access the mechanical and SSD drive simultaneously, storagereview found. WD will probably revise the firmware.

November 25, 2013 | 08:31 AM - Posted by Robert23655124 (not verified)

Holy crap my laptop has a new friend :)

November 25, 2013 | 09:06 AM - Posted by mAxius

toss it in a ps4

November 25, 2013 | 09:24 AM - Posted by Ryan Shrout

Won't work as the PS4 won't be able to access the 1TB portion.  And I don't know if the PS4 can handle working on more than one drive that shows up internally. 

A lot of questions there...  :)

November 25, 2013 | 11:51 AM - Posted by Allyn Malventano

Yeah from what we've seen of the PS4 partitioning scheme, it *might* work if the 1TB portion was already unlocked on a PC and then all partitions deleted prior to installing it into the PS4, but then you're stuck with not knowing where the PS4 puts its data. It's definitely not aware of this SSD / HDD layout, so it'd be a crap shoot as far as performance goes, and it may not like data spanning the logical crossover between the two physical devices.

November 25, 2013 | 10:15 AM - Posted by Anonymous (not verified)

Isn't it better to go with a large 3 or 4 TB drive and pair that with a small SSD (like 60Gb) and just do intel SSD catching?

You end up with a huge "hybrid" drive that's pretty fast.

Your thoughts Allyn?

November 25, 2013 | 11:33 AM - Posted by Allyn Malventano

Sure that would work great - in a desktop. This is meant for laptops with a single 2.5" bay. Even a laptop with dual bays would benefit from an SSD and HDD in separate bays, and be more cost effective as well.

November 25, 2013 | 06:31 PM - Posted by NightWinggl (not verified)

What about a situation where you could use an Msata SSD with a HDD in the 2.5" bay?

November 26, 2013 | 11:24 AM - Posted by Allyn Malventano

It's still a bit of a coin toss, but if that same laptop is RST caching capable, you can get a better overall benefit by going with a fast 60GB mSATA caching a larger 2.5" HDD.

November 25, 2013 | 11:38 AM - Posted by PaulJ (not verified)

Aside from the lack of Linux/OSX support out of the box. I wonder if you provision it on a Windows box and then plug it onto a Linux or OSX machine... should be able to see both drives.

If this is the case, then this would make a great drive for ZFS NAS/SAN boxes.

November 25, 2013 | 11:57 AM - Posted by Allyn Malventano

It's possible, and this would be completely unsupported by WD, but you'd need to partition the SSD space under a PC, then let the WD driver unlock and partition the HDD space. Once this is done, you could reformat those two partition spaces to whichever file systems you wanted, but you'd need to maintain the *exact* offset and total sector figures for those two MBR entries or you risk seeing some odd performance from the SSD, HDD, or both.

You should be able to make multiple partitions within the SSD space (for power users who want to do custom multiple boot setups), but the HDD partition *must* start at the same offset that is created by the WD software.

November 25, 2013 | 01:55 PM - Posted by Anonymous (not verified)

The main problem this disc has is the 9.5mm thickness. most drives that fit this disc will have a optical bay, which with a cheap 11$ adapter can become a new home for your 90$ ssd. the laptops that don't have an optical bay usually only fit a 7mm disc, most ultrabooks with 2.5" slots as an example.

People and reviewers should really know that this possibility exists and is VERY much cheaper than the approach WD has taken.

November 25, 2013 | 06:39 PM - Posted by NightWinggl (not verified)

Agreed. My Laptop (Thinkpad T430s) has Msata, the 2.5" Bay, and the Optical Bay and I got the Ultrabay adapter for about $11 on ebay. It just seems like I have a lot of way cheaper options to get the same amount of speed and storage. I realize I have more options than others.

If this WD drive was 7mm, it would be far more impressive in my mind though. The height really limits the machines it can go into.

November 25, 2013 | 08:49 PM - Posted by danwat1234 (not verified)

9.5mm has been industry standard for a long time now, it's just limiting in that some new thin laptops may be limited to 7mm drives.

November 25, 2013 | 03:28 PM - Posted by Anonymous (not verified)

Nice concept, getting 2 drives onto one SATA port! I can not wait to see what the other drive manfactures will come up with to compete with this! Who would have thought that the thin hard drives ment for Ultrabook/thin and light laptops, also have opened up some intresting possabilities for regular form factor laptops! I hope they get the thin laptop hard drives even thinner, maybe someone will stack 2 thin 1 TB hard drives togather, and make a dual drive onto one laptop SATA port RAID drive, for regular form factor laptops! Maybe 2 thin hard drives In a RAID configuration with a larger than 8GB SLC SSD data Cache. I'll have to wait for the Linux drivers to become available for this drive!

November 25, 2013 | 06:41 PM - Posted by amadsilentthirst

This is great for a laptop. well done WD.

I'd like to see a 3.5" one for a desktop, some of us like small cases and only having "one" drive is quite an advantage.

Maybe something like a 250GB SSD with a 4TB green platter.

Thanks for the review Allyn (inappropriatecontext?)

December 9, 2013 | 08:18 PM - Posted by Allyn Malventano

You've got much more room in a desktop, as well as more SATA ports and bays to work with, so it's far easier to just add an SSD to a large HDD. No need to pay the cost premuim for WD's technology-shrinking voodoo.

November 26, 2013 | 02:40 AM - Posted by Anonymous (not verified)

Allyn, thanks for the review.

In the WD software, is there an option to use the SSD as a cache drive? I know there's third-party software to do this, but does WD support it in their software?

November 26, 2013 | 11:27 AM - Posted by Allyn Malventano

No such option, and no way to enable it in other ways (i.e. Intel RST would not work as the drive appears as a single combined physical volume).

November 26, 2013 | 05:37 AM - Posted by Anonymous (not verified)

Most people considering this type of hardware for their laptop or PC wil look at a SSHD drive as well (SSHD = HDD Drive backed with SSD Cache).

In this review a comparison to such a drive type lacks as well as the comparison to a drive of another major vendor; Seagate. Comparing this drive just to SSD's and HDD's is not enough in my opinion.

November 26, 2013 | 11:29 AM - Posted by Allyn Malventano

You seem to have overlooked this page of the review, where I compared the SSD and HDD portions, directly against both 500GB and 1TB versions of the exact Seagate SSHD you're referring to.

The SSHD models do not appear on the other tests because those tests can not be cached by the SSHD and therefore give inaccurate results.

November 26, 2013 | 02:16 PM - Posted by sixstringrick

Want it! Want it now! When and where can I get it.

December 9, 2013 | 08:16 PM - Posted by Allyn Malventano


November 29, 2013 | 10:32 AM - Posted by Anonymous (not verified)

Can u secure erase the SSD part like other SSD on the market ?
I mean, i have a samsung 840 ssd at this time, and i can secure erase it (reset the nand, internal secure erase command) by parted magic, its way faster and quicker than secure erasing with multiple pass a HDD.

Since the device is in two part, one regular HDD and one SSD but pluged into one Sata port. Did this will work ?

December 9, 2013 | 08:14 PM - Posted by Allyn Malventano

You can, but the HDD partition must be removed and it must be reverted back to SSD-only mode prior to doing so. Only the SSD portion will be secure erased. To securely wipe the HDD portion, you'd have to do it the old fashioned way, with a partition-based wipe tool.

December 1, 2013 | 03:23 AM - Posted by Neshi (not verified)


Do you think there would have been a way for WD to have this drive show up as 2 independent drives in the system (does sata support 2 drives on the same link) if it does is there any benefit to doing it the way they currently are?

December 9, 2013 | 08:15 PM - Posted by Allyn Malventano

I would imagine they approached this as an initial design, but it would require port multiplication, which is very iffy as far as being supported by all of the various mobile chipsets.

December 2, 2013 | 11:52 PM - Posted by aselwyn1

i wonder if you can put this in a ps4?

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