I have added both internal IDE and external Firewire drives to my system (Quicksilver 733) for video editing. No problems either way. I've heard that either 5400 or 7200RPM will work fine. Mine are all the higher speed. If you wish to add internal, you need to get another IDE controller card. I have 4 internal drives in my system with no problems (heat or otherwise). The controllers and internal disks are very easy to install and if you need, there are internet sites that take you through step by step. Two of my firewire drives are from OWC and work great. Again I have the 7200RPM disks and the only time I had problems was when I stacked them with an external CD device on top. They overheated - no internal fans on these units. I did have problems with another firewire disk unit. I purchased a firewire box (forget the brand) which has the 911 chip support and allows one to purchase a disk separately (or a CD writer or other device) and insert into the box. On occasion, this unit gave an error message during video editing that it could not keep up. Don't know if it was the firewire box or the disk (a high speed Maxtor). Either approach should be OK. I'm guessing that the firewire approach will be a little more expensive. As for size, I've always purchased the largest economical size available (look at cost per gigabyte). Mike (formerly from the Iron Range) > >I have a G4/933 (768M RAM, 2 internal 60G's) and need to add >significant hard drive capacity for digital video conversion and >storage. How large a drive can I install, and how many more >(considering the fact that there are two internal's already? Also, >would it be better to add an external firewire drive, and - if so - >how large can I go? > > >Thank you! > >Steve Phillips >Two Harbors, Minnesota