As Apple rolled out other models of Mac laptop and desktop systems, SSD's became a Build-To-Order option in select models, often at a stiff premium. Many Do-It-Yourselfer's opted to perform an SSD upgrade themselves after the purchase. With the majority of SSD's in the 2.5" laptop drive format - most were drop-in replacements in MacBook and Mac mini systems. Until full-size 3.5" Solid-State drives arrived, many used disk adapter brackets and cases in Macintosh Pro towers and iMac models.

In the years since - SSD storage has made mind-blowing performance improvements. Drive capacity increased at ever more affordable prices and performance doubled - then quadrupled as rapidly evolving SSD controller chipsets and Firmware advanced.

It's the increased density of the flash NAND chips that's pointing towards the future. The latest MacBook Air's with custom SSD module are pointing to a future where our notion of a 'hard drive' doesn't necessarily have to occupy the paperback size space of a 3.5" drive, or a laptop disk's deck-of-cards form factor. To deliver ever more compact and lightweight mobile computers - our current notions of traditional spinning platter drives and their bulk is likely to end sooner than you think.

As with the new MacBook Air's, an off-the-shelf retail SSD drive upgrade or replacement isn't an option as Apple implements a proprietary mini SSD card in a different form-factor. OWC is the sole manufacturer who offers a higher-capacity (and very expensive) 512 GB SSD card upgrade alternative for these new Mac laptop models.