A Parallel ATA hard drive attached to a Power Mac G5 computer via an adapter does not work.
Solution
Power Mac G5 computers have only Serial ATA busses. There are third-party adapters to connect Parallel ATA hard drives to Serial ATA busses, but these adapters are not supported for use on the Power Mac G5 computer. If you wish to upgrade your hard drive or add a second hard drive, you should use only native Serial ATA hard drives.
A native Serial ATA hard drive has the Serial ATA data and power connector on the hard drive and does not require the use of adapters or special cables.