WD Black² Dual Drive review

Jonathan Bray January 10, 2014

£230

Price when reviewed

One of the most transformative upgrades you can make to an ageing laptop is to swap the mechanical hard disk for an SSD; however, since the cost per gigabyte is much higher than for mechanical disks, the switch usually means sacrificing capacity.

WD aims to solve that problem with its Black[sup]2[/sup] dual drive, which combines a 120GB SSD and a 1TB mechanical hard disk in a single 2.5in shell. The idea is that you can run your OS and applications from the fast SSD, while – as with many desktop PCs – storing your movies, music and photos on the slower but more capacious mechanical disk.

The drive is 9.5mm thick, and uses a single SATA/600 data and power connector, so it should fit in most laptops with a user-accessible drive bay. The first time the Black[sup]2[/sup] is hooked up, it appears to Windows as a standard 120GB SSD, ready for you to clone your system or install a fresh copy of Windows onto. With this done – using the free WD-branded copy of Acronis True Image and the USB-to-SATA cable that’s helpfully supplied – you can boot into the system and run WD’s proprietary software to set up the 1TB mechanical hard disk as a second partition.

So how does it perform? We used the Black[sup]2[/sup] to upgrade an Ivy Bridge Core i7-powered Dell laptop, replacing the standard 5,400rpm 1TB HDD. We found Windows 7’s boot speed halved from 40 seconds to a speedy 21 seconds, and our benchmarks also saw a performance boost: the Responsiveness element of the benchmarks, which opens and closes Explorer windows and a series of apps, showed an 11% improvement.

WD Black2 Dual Drive

We then connected the Black[sup]2[/sup] to our standard test rig, and ran AS SSD on the SSD partition to determine absolute read and write performance. In this test, the Black[sup]2[/sup] returned sequential read and write speeds of 359MB/sec and 140MB/sec, and 4K read and write speeds of 25MB/sec and 46MB/sec respectively. This isn’t anywhere near as high as our A-List SSD, the Samsung 840 Pro, but there’s plenty of speed here to give an older laptop a big lift.

Finally, to measure the performance impact of accessing both partitions simultaneously, we ran AS SSD’s sequential test on both the SSD and the mechanical disk at the same time. Read and write speeds on the SSD to dropped to 95MB/sec and 77MB/sec respectively, although the system remained perfectly responsive.

The idea of squeezing an SSD and HDD together into a single case is attractive, but it only makes sense if the price is significantly cheaper than a standalone SSD. Fortunately, the dual drive scores well on this front: its £230 price works out to 22p per unformatted gigabyte. The Samsung 840 Pro costs more than three times this, and even the cheaper version – the 840 Evo – costs more than double.

The Black[sup]2[/sup] dual drive may not be the fastest SSD around, but if you’re after a performance boost for your single-bay laptop, it’s the only drive we’ve seen that offers both speed and capacity, making it a highly appealing upgrade.