Best settings for 80 track recording to HD3 at 48k

[STUDiogeek]

Hi,
What are the best settings for capturing 80 tracks to an HD3 at 48k for two or more hours. The mac is a single 1.25 with 768 megs of ram. The drive is a 7200 rpm internal. This very setup usually will go for hours but sometimes will give a disk access error message. I'm trying to find the optimal settings for this application but the same settings seem to give mixed results. The internal record drive is usually empty at the start. What should I be doing to make this MOST successful on a nightly basis? There are no edits or plug-ins, just high track counts. What elements most affect the systems ability to capture this many tracks for that long a period of time? Am I correct in assuming that maxing out the ram will assist the buffering process? to what degree?
Thanks,
SG