I will not repeat all of the problems I had interfacing a new Seagae Serial ATA drive to this G4 AGP using OSX 10.4 and various SATA/PCI cards. The card that finally worked was the SIIG Serial-ATA PCI-M. You may recall that after I finally got the drive to mount I could NOT find it with the Apple System Profiler. The SATA drive did not show up under ATA, Serial-ATA or PCI. After all the discussion on Erase vs. Partition, I decided to wipe the new SATA drive using the Partition option in the OSX 10.4 Disk Utility and used Carbon Copy Cloner to clone my Primary drive to the new SATA BackUp drive. Guess what? The new drive now shows up in the Apple System Profiler under ATA. As expected it does not show up as a S-ATA drive. ------ ST380817AS: Capacity: 74.53 GB Model: ST380817AS Revision: 3.42 Serial Number: 3MR008CT ----- As expected it does not show up under the Serial-ATA option. The SIIG SATA PCI-M card shows up under the PCI option as ---------- 2-ch SATA: Name: SIIG-3512-NR3 Type: ata Bus: PCI Slot: SLOT-B Vendor ID: 0x1095 Device ID: 0x3512 Subsystem Vendor ID: 0x4895 Subsystem ID: 0x3512 ROM Revision: 1.0 Revision ID: 0x0002 ----------- I am now 90% sure using the Partition option really helped. I may never use the Erase again. Thanks to all that responded Dick ps: Yes, I can boot from the CCC cloned backup SATA drive. Dick