Western Digital Black2 – Review of 2.5″ Dual Drive (SSD + HDD)


WD Black2 is world’s first SSD+HDD dual-drive that combines a 120GB of SSD for OS & programs and a 1TB hard drive for data in a single 2.5-inch shell.

Choosing between solid state drives (SSDs) and hard disk drives (HDDs) is quite tough, especially when it comes to laptops or some other small form factor systems. SSDs offer great speeds, but they’re quite expensive on a per-GB basis. On the other hand, HDDs offer a better value per GB, but they are not as fast as SSDs. Western Digital has smartly solved this problem by introducing world’s first SSD+HDD dual-drive called WD Black2. With this revolutionary combo drive, people can now enjoy SSD performance and access high capacity storage in a single package. It features a 120GB solid state drive as well as a 1TB mechanical hard drive, and they both fit in the same bay. This means, you can use the 120 GB portion for your Operating System and important programs, and the 1 TB hard drive for storing media and other files. Now, let’s take a closer look at Black2.

WD Black2 SSD/HDD dual drive

WD Black2 Dual Drive Overview

Western Digital has provided their unique, high-quality design to this dual drive as well. The top of the drive has a very glossy reflective black finish on it, along with a ‘WD Black2’ logo in golden color. Plus, there is an outline of a PCB (Printed Circuit Board) etched on the end.


Although Black2 is a bit thicker, it looks almost no different than a traditional 2.5 inch solid state drive. Normally, most 2.5 inch SSDs measure in only 7mm thick, whereas Black2 is 9.5mm thick. This means, it might not fit in your Ultrabook, but it will fit in normal laptops or laptops with a small form factor. There are two mounting points on each side of the drive.

Now, when you look at the rear side of the drive, you’ll realize that this is not your ordinary SSD; it features a mechanical drive as well. The mechanical drive used in Black2 is actually a WD Blue 1TB 5400 RPM drive, whereas the SSD portion is made up of two 64 GB 20 nm MLC NAND modules, an advanced JMicron JMF667H 4-channel controller and 1GB NANYA DRAM chip. Plus, there’s a smaller PCB portion with a Marvell bridge chip in it.

With two different drives, you might think that there will be two separate connections for them. But no, you’re wrong. The Marvell bridge chip makes everything work together in perfect harmony as a single drive. It requires just a single SATA data and power connection for its working.

The JMicron JMF667H controller supports SATA 6GB/s, which provides read speed of 350 MB/s and a sequential write speed of 140 MB/s. No doubt, this is much slower than current SSDs, still it’s quite faster than any mechanical HDDs out there. And coming to Black2’s mechanical hard drive, it supports SATA 6GB/s with a max transfer speed of 140 MB/s and a latency of 5.5 ms.

Initial Setup & Installation

Just like you do for any other drive, go ahead and install the WD Black2 dual-drive in your system. When it is first installed, your device will only recognize the 128GB SSD. To unlock the mechanical side of the drive, you’ll have to download the WD Black2 software. Once that is done, you can use the included USB drive to open the WD Black2 drive product page. From there, you can easily navigate to download the page and get the software installed. Unfortunately, this is the only way to unlock the drive, and so you must have an internet connection to do this. Once the software is installed successfully, you’ll find that the drive is now partitioned into two separate drives.

Simultaneous HDD/SSD Performance

A test was conducted to analyze the performance of Black2 when both the drives are used simultaneously. It was found that when both drives received read/write activity simultaneously, they were pretty responsive, but performance dropped notably. This means, if the SSD portion can deliver read speeds of 450MB/s and the HDD 110MB/s, the total performance of the dual-drive will never exceed the limit of SATA 6GB/s port. However, when the drives received opposite workloads, the tests locked up indicating that the controller may not be able to handle multiple streams of contradictory read/write activity in certain circumstances. Rebooting the system and reinstalling the drivers did resolve the issue, but it’s really worth noting that the drive failed to perform up to expectations. Nevertheless, WD has admitted that their future releases will have enhanced stability and performance, and so it is expected that multi-drive performance will improve over time.

Price and Availability

The idea of combining a SSD and HDD together into a single case is definitely quite innovative and attractive, but it only makes sense if the price of this dual-drive is less than a standalone SSD. Fortunately, the Black2 drive scores well on this front as well. Priced at just $299, it is currently available via Western Digital’s WD online store and other outlets such as Amazon.It comes with a five year warranty, and the kit includes WD Black2 Dual Drive, Quick Install Guide, SATA to USB Cable (for software download), USB Web Key (for software download) and Warranty Guide.


The Black2 dual drive may not be the fastest Solid State Drive around, but if you want to boost the performance of your single-bay laptop, then Black2 is perfect for you. It’s the only drive available that offers both speed and lots of storage space at a time.


  • 2 drives in one!
  • Outperforms specifications
  • Sleek design
  • Compatible with all Windows system that supports 9.5mm drives
  • SATA to USB 3.0 adapter & Acronis TrueImage software included


  • SSD performance is weak than what is currently available
  • Drive unlock software not included (you must download it)
  • Compatible with Windows only

The WD Black2 Specifications at a glance:

  • Model Number: WD1001X06XDTL
  • Form factor: 2.5-inch
  • Interface: SATA 6 Gb/s
  • Performance (SSD): 350MB/s read, 140MB/s write
  • Load/unload cycles: 600,000
  • Non-recoverable read errors per bits read: <1 in 1014
  • Limited warranty (years): 5
  • Average power requirements (W)
    • Idle: .9
    • Read/Write: 1.8
    • Standby/Sleep: .9
  • Temperature (°C) Operating: 0 to 60
  • Non-operating: -40 to 70
  • Shock (Gs)
    • Operating (2 ms, read): 65
    • Operating (2 ms, write): 30
    • Non-operating (2 ms): 350
  • Acoustics (dBA)
    • Seek (average): 21
    • Idle: 20
  • Physical Dimensions: 9.5mm x 100.20 x 69.85
  • Weight (lb./kg, ± 10%): 0.28/0.125

Western Digital Black2 Dual Drive Unboxing & Overview video from youtube: