How do you upgrade the hard drives in the Mac Pro? How many drives of what type are supported?

Much like upgrading the memory, upgrading the hard drives in the Mac Pro models is simple, but some basic instructions are helpful nevertheless.

All Mac Pro models have "four independent 3Gb/s Serial ATA cable-free, direct attach hard drive bays" with "four internal hard drive carriers included", and precisely the hard drives must meet these specifications:

• Type: SATA 3 Gbps*
• Width: 3.9 inches (102 mm)
• Depth: 5.7 inches (147 mm)
• Height: 1.0 inch

*The Mac Pro "Eight Core" 2.8 (Early 2008) and the "Early 2009" models -- the Mac Pro "Quad Core" 2.66 (2009/Nehalem) and Mac Pro "Eight Core" 2.26 (2009/Nehalem) -- also support Serial Attached SCSI (SAS) drives with the installation of the Mac Pro RAID card.

By default, a single 3Gb/s Serial ATA (8 Mb cache) hard drive is installed in the first of four bays. The original Mac Pro Quad 2.66 formally supports a total capacity of 2 TB and the "Early 2008" and "Early 2009" models formally support up to 4 TB. Although not mentioned on Apple's primary website, 1.5Gb/s Serial ATA hard drives also will work in all Mac Pro models and the Developer's Notes show an additional "two unpopulated 3 Gbps SATA buses for expansion".

Unofficially, as first noted by site sponsor Other World Computing, the "Early 2009" models also can support a fifth hard drive by using the second 5.25" optical drive bay.

Apple provides a PDF that covers upgrading the hard drives in the Mac Pro -- and covers the same material in the instruction manuals for each model as well -- but perhaps even better, Other World Computing provides step-by-step videos of the process.

This video covers upgrading the hard drive in the original and "Early 2008" models:

Although the process is quite similar to the earlier systems, this video covers upgrading the hard drive in the "Early 2009" models:

For even more information on hard drives in the Mac Pro, you may wish to read special reports on exceeding the maximum formally supported drive capacity in RAID sets and finding the fastest possible boot drive from the always excellent BareFeats.

In addition to providing helpful upgrade videos, as you would expect, Other World Computing also sells high quality hard drives and memory for the Mac Pro models.