I've seen the right answer posted. Your motherboard can only see 128GB. Even if you partition the drive, it will still not recognize the whole available disk space. Been there, done that. In my case, I put in 160GB IDE drive. A bit was wasted, but you get a bit more than if you put in a 120GB or 80GB. There is a software solution available, and I think I remember seeing it available at Other World Computer. They're kind of Mac fans and have a lot of Mac stuff there. Prices are not too bad, either. The software solution uses some kind of gimmick to help the board see the whole drive. I'm not a fan of this type of solution, but it probably works O.K.. The other solution is to get a SATA card, such as a Seritek 1s2. Plug it into an available PCI slot, and you can install a SATA I or SATA II drive. It will be supported to at least 1GB, or even more, and this card support the drive as a boot drive. Be careful, there are some SATA cards out there that DO NOT support boot. Make sure the card you use does, if you choose this route. Also, the card MUST be Mac specific, a PC card will not work. The Seritek card is about $65.00, well worth it if you plan to keep and pile stuff into the machine. Sonnet also has a card that works well for this.