So I take it the two 10K drives are SCSI and can I assume at least U160/320 drives as well ?!?
The 30GB startup drive is what concerns me however.
When the stuttering/lag occurs do you notice if the HD busy light is really on a tear ?!?
My guess that this startup drive is not really optimized for your workstation in that it's most likely too slow and that the OS is not optimized to the paging file.
Here's what you should do to test this out. First resize the the paging file if it's on the 30GB drive to something small, I think the minimum size is 2MB! Set it for this and then create another paging file on your much faster SCSI drives for say something like 512MB for both the min/max size. Basically you have enough ram to not worry about paging but this doesn't stop Windows from using it anyway

Then I would d/l and run
X-Setup which has a lot of nice optimization features for the OS and various other things too

The one you want to use most is the one that will tell the OS, in this case Win 2K Pro, that you want to force using all available RAM before paging! Windows by default goes the other way around!
If this fails then I would like to know what the specs were on the other PC or PC's that you've run these anims on successfully?!? I figured the MAC would be ok as it's probably optimized for this kind of playback already. But you mentioned it worked on another PC so if we can compare the specs to yours we maybe able to figure out the bottleneck in your system config
