Our testing has shown that the performance, in terms of track counts, is not as high with internal drives (i.e. IDE/ATA) as external (i.e. SCSI). Part of this is because you can only have one or two, IDE/ATA drives internally, while for maximum track count you can use 4 external drives.FireWire vs. SCSI? Our testing isn't done yet with FireWire drives, but for the highest track count (and expense, unfortunately), you need SCSI. BUT...That's based on our test routines, which are extremely rigorous, and may not reflect what you personally need from your system. If internal drives or FireWire drives are working for you so far, great.I would discourage you from spreading media files from the same session across different partitions of the same drive. Partitioning a drive looks like you have separate drives on the desktop, but in fact you still have only one disk head. Spreading files between partitions causes the head to have to seek farther, so you actually decrease your performance relative to having one big partition. If you have multiple drives, however, you have multiple disk heads creating more throughput and seeking less, so you get superior performance over one drive.If your main concern on adding a drive/partitions for video playback, I'd suggest that you get an external FireWire drive. They are very large (80 GB +), and very inexpensive. They are also excellent for video playback, even though they have lower RPMs. This is because video files tend to be contiguous, so the heads have to do a lot less seeking. Plus, with the video streaming on the FireWire bus, you aren't clogging up the internal bus, so you have more bandwidth for audio.