If you happen to pop off the bottom casing of your laptop and find out that your 2.5? disk drive is nowhere to be found, do not panic. Instead, it's possible that your laptop may be utilizing a different form factor than the 2.5? drive. When it comes to solid-state drives, there are three main form factors that you should know about. The first, as we have already mentioned is the 2.5? form factor, which is the standard size for most desktop and laptop systems. The second, and the primary focus of today's review, is a mSATA drive. A mSATA drive is roughly 2? by 1? in total size, and ideally used in the slim ultra books. The final size that you should know and is quickly increasing in popularity is the M.2 form factor, which is roughly 3? by 0.75?. Looking back down at your open laptop, you may just see that mSATA, or even a M.2 drive. Regardless, it is still an easy upgrade just like the 2.5? form factor drive.