Our solution is less elegant, but just as effective as the first two. The problem is simple: Our notebook computer is a 15" MacBook Pro. Apple doesn’t support replacing the optical drive with a hard disk, and this notebook has only one 2.5" slot.
Replace The Optical Drive With A Hard disk
Despite this limitation, there is a solution – the OptiBay from MCE. This is a case containing an adapter that lets you connect a hard disk in place of the optical drive.
Obviously, since our notebook uses an ATA optical drive, the hard disk has to use the same interface. OptiBays exist for MacBook and MacBook Pro, in two versions – for computers that use a slim optical drive (12.5 mm thick) and for ones that use an ultra-slim (9.5 mm) drive. OptiBays are usable on any computer, but need a few adaptations, including to the tray. The OptiBay costs $99, but you can order it with a hard disk or an external optical drive.
Choosing Components: The Hard Disk
Once we had the adapter, we needed to choose a hard disk and SSD. For the hard disk, we needed an ATA model with a decent capacity (at least 120 GB). The speed didn’t matter much since the disk would only be used to store data – all our applications will be on the SSD. We chose a Samsung HM160 (5,400 rpm, 160 GB). Note that the most recent 2.5" hard disks are no longer made in ATA and only in SATA format, which limits the capacity (250-GB models exist, but they’re rare).
Choosing Components: The SSD
The second problem was which SSD to choose. First, it had to be a SATA drive, because the machine’s original hard disk uses that interface. Then, its capacity had to be at least 32 GB so that we could use a recent operating system like Mac OS X Leopard or Windows Vista with no problem and still have all our applications on the SSD. We ended up choosing a 32-GB Mtron MOBI 3000. This fast SSD (the specs claim a 100 MB/s read speed and 80 MB/s write speed) uses a SATA interface and is currently one of most highly reputed SSD models.