A while back, several people posted questions on this problem (unable to create or recognize partitions beyond the 128 GB address on ATA devices larger than 128GB), which I have summarized at bottom. I have heard that this problem affects all Mac OS versions when used on PPC's prior to the G5. (check ATA controller specs on specific model) I have not yet tried the software product myself, but a few drive OEMs have bundled Intech's SpeedTools which is reputed to solve this problem for ATA drives on both OS 9 and X. I presume this is done using a replacement driver for the extensions folder in combination with a special format/partition utility. This product may have a similar solution for SCSI drives. Check out http://www.speedtools.com/ and google 'speedtools mac 128GB' to find remarks from others. I have also heard that installing the newer ATA/133 controller PCI expansion card also does the trick. -mp =============================== Previous posts asked... Name: nottinghillguy Date: April 07, 2005 at 18:03:09 Pacific Homepage: Paulsen Multimedia Subject: Formating ATA drives over 128 GB OS: Mac Os 10.35 CPU/Ram: 1 GHz/512 MB System Manufacturer: Apple Comment: Please give me advice on how to format a new ATA hard drive that is larger than 128 GB to it's full capacity using Mac OS X or even OS 9.2 My new 300 GB DiamondMax 10 shows up as 128 GB in size when I would like to use it's full 300 Gb capacity. Apple's Disk Utility only sees 128 GB, and as a result, formats the larger than 128 GB hard drives as only 128 GB in size. Response... Only newer Macs can use a drive over 128GB. It's an IDE Controller limit. You need to get an ATA/IDE 133 controller PCI card to install and you can use any size drive.