It's no secret that hard drives – with or without RAID – have long been the weakest link in an avid personal computer, but until recently, flash-based alternatives weren't affordable enough for the masses. In 2009, SSDs, including the original Vertex from OCZ, fetched $ 3.00 per gigabyte, or about $ 350 for a 120GB model, a little more than a 2TB hard drive at the time, which was only $ 0.06 cost per gigabyte.

Since then, prices have dropped significantly. High-end SSDs like the Samsung SSD 840 Evo cost only $ 0.75 per gigabyte for a 120 GB version. That's still a serious premium over a drive like the Western Digital Black 3TB, which costs just $ 0.06 per gigabyte, while 2.5-inch laptop drives like the WD Blue 1TB for $ 0.09 each Gig are available. This discrepancy can make it difficult to balance speed and space.

Granted, the price gap isn't as extreme as it used to be, but a lot of people are still faced with the limitations of one technology or another. For example, laptop users often have to choose between a faster experience with less storage space or a slower experience with more storage space. Around $ 100 can buy a 120GB SSD or 1TB hard drive, but we still dream of flash drives that match the price and capacity of traditional storage.

In the meantime, WD has developed a solution for laptop users who have a single 2.5-inch bay (which is the vast majority of them). The company has developed a notebook drive that contains both a 120GB SSD and a 1TB hard drive.It's not a standard hybrid configuration like Seagate's Momentus XT drives, which have ample magnetic storage with little NAND -Combine memories to cache frequently used data.

These types of setups are a significant improvement over traditional hard drives, but are significantly slower than a full-fledged SSD for most tasks. The Black2 also packs both technologies into one drive, but it simply does what desktop users have been doing for years by making the flash part a primary boot drive, with the hard drives serving as mass storage. The difference is that the Black2 only uses a single slot.

At $ 300, that's $ 0.27 per gigabyte if you get the full capacity of 1.2TB or less than half the price of a Samsung SSD 840 Evo 120GB and not much more than the 0 $ .09 per gigabyte you pay for a standard 1TB account for 2.5-inch drive considering the package includes a 120GB SSD. As always, we're here to find out what the hell that quarter per gigabyte is getting you in terms of performance.

WD Black2 Hybrid HDD in detail

In terms of dimensions, the WD Black2 looks like any other 2.5-inch drive, measuring 100.20 x 69.85 x 9.50 mm and weighing just 125 g. However, its aesthetic differs in that it is not completely encased in steel or aluminum, a thin circuit board on the bottom, part of which has the 120GB SSD.

According to WD, the Black2 only consumes 1.8W and 0.9W while idling or sleeping. Since it's not just an SSD, the drive can only handle 30G or 350G shock if it is not operational while SSDs can safely handle up to 1500 G because they have no moving parts.

Squeezing an SSD and hard drive together in a tiny package is not easy. As a result, the drive is 9.5 mm thick, while most 2.5-inch drives are only 7 mm.

On the underside of the Black2 is a conventional hard drive with a small printed circuit board that is attached to the case with two 500 GB hard disks. This board has a Marvell SATA bridge chip with which the individual SATA interface can communicate with both the SSD and the HDD via the same partition assignment.

We found the SSD part of the drive after removing the top layer, which is held in place with four small screws and lots of double-sided tape. WD equipped the Black2 with a JMicron 667H controller, two 64 GB MLC NAND chips and a Nanya DRAM cache chip.

The choice of controller is interesting as JMicron doesn't have the best reputation. While it's been a while since we've tested an SSD with one of the company's controllers and have no experience with that particular part, all of the previous JMicron controllers have been flawed.

As expected, the JMicron 667H supports SATA 6 Gbit / s, which enables a read throughput of 350 MB / s and a write speed of 140 MB / s. Both values ​​are quite low for a modern SSD, as the Samsung Evo 120 GB has read and write rates of 540 MB / s and 410 MB / s.

The hard drive also supports SATA 6 Gbit / s, but has a maximum transfer speed of 140 MB / s with an average latency of 5.5 ms.

Since the Black2 is primarily designed for laptops with a 2.5-inch drive slot, the migration of your data from your existing laptop drive to the new one should be optimized. WD includes a very useful USB to SATA adapter cable for operating system cloning that can also be used to turn your old laptop hard drive into a portable storage device.

The company also built in a USB stick, but it's not a storage device at all. Surprisingly, the "device" just launches your default browser and sends it to the WD download site for the latest driver and clone software.