The MCE OptiBay drive enclosure is an essential item 1. SSD disk drives have extremely quick access times

The MacBook Pro doesn’t have space for a second drive by default, but because it has an optical drive (and most people hardly use them anyway) this can be removed to make way for the new SSD. Since the vast majority of Mac sales are MacBooks, this article describes the basics of installing an additional SSD in your MacBook. Many of the iMac desktops have quite a lot of spare room inside, so it’s possible to install an SSD as a secondary disk drive – this way Mac OS X and all your apps can be kept on the SSD and documents, pictures and other files moved to the larger capacity hard disk. But an SSD will speed up Mac OS X Lion and provide a significant performance boost – applications will open up more speedily and boot-up times will improve noticeably. The only minor downside is that SSD capacities are usually way below those of regular disks and they can be quite expensive too. They provide lightning fast disk access times because there are no moving parts, unlike a traditional spinning hard disk. An SSD (solid state drive) is one of the most worthwhile for your Mac.

Solid state drive for macbook pro 2011