Looking for specs for WD5000L12X-21UJGT0 hybrid SSHD

Hi all,

My son’s new Acer V7 laptop has this WD Black SSHD WD5000L12X-21UJGT0.  Note that this is not the Black^^2 (Black squared) dual hard drive.  As far as I know, WD only sells these to OEMs, and apparently they have a special connector on them, and are only 5mm thick for the ultrabook market.


There is no problem with this SSHD, it seems to be functioning well.  I am just looking for a bit more info on it out of curiosity, such as the actual size of the SS cache on this particular unit.

All I have found so far is that the SS cache component is apparently made by Sandisk in some partnership with WD. 

I gather this is supposed to use the WD_Boost driver.  Are there any diagnostic tools that let you probe the setup, find out what files are cached, etc?



Hi johnbinsc, unfortunately little information is available for this model outside of interface and RPM. 


Well, in answer to my own question, you can get some good information from the WDBoost driver download.  Just download it and extract the zip file to a folder. There is a file “Hybrid_Capacity_Data.xml” that can be opened with a browser.  Searching through it I found:


– Bridge SATA3 Std 500GB , 500GB, 16GB - MiB -

ModelMatch WD5000%12X-21%%%%%

FlashStartLBA 976775168

FlashEndLBA 1008052399

So I guess that means that this particular SSHD has a 16GB SSD component.

The best bit of info I found on the web about these SSHD’s in from the MSI web site.  Search for:

How To Install Windows OS on WD Solid State Hybrid Drive1_3.pdf

I will be doing some exploring based on the info in that document.

Thanks for the information. However, it would have been more helpful if you had posted the URL instead of making everyone search for it. :slight_smile:

Anyway, here is one link that I found:


The ZIP contains the following instructions:

“How To Install Windows OS on WD Solid State Hybrid Drive1_3.pdf”

It also contains 32-bit and 64-bit versions of WdHybrid.exe which is a diagnostic/reporting tool (not a driver).

ISTM you could determine the NAND flash capacity by typing …

WdHybrid -d? (lists the drives found)

WdHybrid -status -dn (reports the NAND flash MiB capacity for drive n)

WdHybrid -test4 -dn (performs full SSD read verify test)

Here is the readme.txt:


Windows console tool to enable or disable the SSD LBA reporting on a WD bridged hybrid drive. It can also test and display the LBA values corresponding to the HDD and SSD.

Changes in version 1.6:

* -d? option ignores external USB drives in the list of drives found.
* -status option reports the NAND flash MiB capacity for WD SSHD drives with 02.XXXXX firmware.


WdHybrid [-enable|-disable|-status|-test<n>|-d?] [-d<n>] [-?]


-d? List the drives found
-d<n> Select drive number <n> (default is 0)
-enable Enable SSD reporting
-disable Disable SSD reporting
-status Show if SSD is enabled or disabled and LBA values
-test1 HDD SMART DST short
-test2 HDD SMART DST long
-test3 HDD SMART DST conveyance
-test4 Full SSD read verify test (256 sectors at a time)
-? This help message

If no arguments are given, it defaults to -status

Exit Codes:

0 - Pass
1 - Fail


WDHybrid v1.6 may not report a read scan error on the SSD with AMD drivers and prior. For AMD systems, AMD driver and Microsoft inbox drivers will properly report SSD read scan errors.