How to install a SATA Hard Drive for a Apple G5 Tower machine?
The Power Mac G5 computer can accommodate two serial ATA hard drives in its internal hard drive bay. In most configurations, a single hard drive occupies the top portion of the bay.
These instructions describe how to replace a hard drive. If you are installing an additional drive in the empty slot in the bay, be sure the drive meets the following specifications:
Type: serial ATA
Width: 3.9 inches (102 mm)
Depth: 5.7 inches (147 mm)
Height: 1.0 inch
Important: Use the original Apple cables that came with the Power Mac G5 when installing SATA hard drives.
Get the information to install a SATA HD for a Apple G5 Tower machine from HERE