The price disparity between solid state and hard disk drives often forces mobile and small form factor users into the unenviable position of choosing performance over capacity. Provided they've got the budget, desktop users needn't compromise, because their systems can accommodate multiple drives of different form factors without issue. But SFF, all-in-one, and mobile systems are usually outfitted with only a single 2.5" drive bay, so if you want the performance of an SSD, but need a large capacity drive, you've got to shell out big bucks for a high-capacity SSD or settle for the lower performance of a hard drive.

WD recently released a totally new class of product that aims to resolve this conundrum, however. The new WD Black 2 Dual-Drive (SSD + HDD) pairs 120GB of solid state storage with a 1TB hard disk, in a single 2.5" device. The WD Black 2 is not a caching solution, though, like some other hard drives outfitted with flash memory. Rather, the WD Black 2 operates as two independent drives-a fast SSD for your OS and most commonly used apps and a large hard drive for bulk storage...