Despite its disadvantages, SSD is breaking into the mainstream due to the proliferation of models and the lower prices that have come in the last year from increased competition and improved production processes. Notably, Intel recently introduced its smaller and less expensive .

Performance sees improvement, too, but the benefits of using an SSD are not apparent across all applications. For now, SSDs force you to accept a trade-off: They offer faster read speeds, but in write speeds they trail 7200-rpm magnetic hard disks (and can even fall short of 5400-rpm hard disks).

Compared with standard hard drives, SSDs are capable of reduced latency, which translates into greater speed in accessing data. For example, Intel says a typical hard-disk drive's latency is 4000 microseconds, while the company's X-25M is rated at 65 microseconds. SSDs have faster seek times than hard-disk drives do, too. Newer drives, such as the X-25M, boost random write performance, which can have a positive impact on system and app responsiveness.

But not all SSDs are created equal. Everything from the source of the NAND flash to the chipsets and controllers to the wear-leveling algorithms used (more on that in a moment) can affect performance. Single-level cell (SLC) flash, for instance, is costlier than multilevel cell (MLC) flash, but it's also capable of greater endurance. Most consumer SSDs today have MLC flash; when drives are significantly pricier or are sold as "enterprise" drives, the reason may be that they have SLC flash.