Is it possible to add a second hard drive to a "Unibody" MacBook or MacBook Pro?

The "Unibody" MacBook and MacBook Pro models are not designed to accommodate a second internal hard drive. In fact, you have to go all the way back to the PowerBook G3 series to find Apple notebooks designed with a second "swappable bay" that could be used to hold a second hard drive, a removable storage drive (floppy, Zip, optical, etc), or even a second battery.

When the MacBook Air was introduced with an external optical drive -- in a design decision no doubt familiar to long-term Mac enthusiasts as an updated version of the PowerBook 2400 (which had an external floppy drive) -- users immediately fell into two camps.

There were users who couldn't believe Apple would make the optical drive an "add on" rather than part of the system and those who thought about it for a moment and realized that they only use the optical drive for occassional troubleshooting and software installation so removing it from the system wasn't a big deal.

If you fall squarely into the latter camp and only find the occassional need for an optical drive, as first noted across the Mac web, MCE offers an "OptiBay" product that replaces the internal optical drive with a second hard drive in the MacBook, MacBook Pro, and PowerBook G4 models.

MCE explains that the OptiBay is:

A high performance laptop hard drive inside a specially designed, lightweight case that's been engineered to the exact same dimensions as your laptop's SuperDrive or Combo drive. . . Besides just appearing different, laptop optical drives and hard drives have very different data connectors as well, so an adapter was developed allowing the hard drive to communicate with your MacBook Pro, MacBook, or PowerBook G4 through the optical drive connector on the motherboard.

Essentially, it's a custom drive sled with an adapter. It's not inexpensive, but for those who would rather have a second internal hard drive than an optical drive in a MacBook, MacBook Pro, or PowerBook G4, it is well worth considering. MCE also sells an external case that can be used to "repackage" the previously internal optical drive for external use.

Site sponsor Other World Computing sells a variety of upgrades for all MacBook, MacBook Pro, and PowerBook G4 systems.