Here is an interesting observation i have become aware of while burning video DVD's in Toast.
My 1.5Ghz PowerBook has 1.5gig of ram running Mac OS X 10.3.8.
I launch the activity viewer and display the 'System Memory' tab. The green 'Free' piece of the pie graph shows around 1.3gig of ram. When i use Toast to burn a video DVD from a backed up VIDEO_TS folder on an external Firewire disk i notice the 'Free' memory quickly erodes during the course of the burn. The 'Free' memory graph depletes to around 17meg, at that point the system starts paging out to disk. After the burn completes i notice the ram used in this process is not returned to the system. It remains around 20 meg. If i eject the external Firewire disk my 'Free' ram is again at 1.2 gig or thereabouts. I have also observed the same situation memory usage behavior when the source VIDEO_TS folder is on the internal ATA disk in the Powerbook. Obviously the internal ATA disk cannot be ejected an thus the ram is NOT returned to the system until after a restart. Strangely there does not seem to be any obvious process in the activity monitor which seems to be using this amount of ram. The kernel_task process jumps to the top however of the list when the 'Real Memory' column is selected, however it does not display usage anywhere near 1gig. The kernel_task on average is using about 70 meg of real memory.
Im looking for detailed explanation of what is involved in this situation an what is the culprit of using so much ram and WHY this ram is not returned to the system until the system is restarted in the case of using the internal ATA drive or until the Firewire external disk is ejected in that case.
I tested 10.3.9 with the same result (i went back to .8 due to other issues).
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