it sounds like ae may be having problems clearing the ram cache…
check your memory and cache settings in the preferences. since you are hitting 87%, it sounds like the max ram cache setting may be too high. adobe recommends that the max ram cache not be set higher than 60%, and never over 90%. also, the default max memory usage is 120%, if you have less than 3gb ram, you can up that some, but should not exceed 200%.
you can also enable the disk cache, if possible set it to a drive that is on a separate controller than your media is or where you are rendering too… so if your media is on a firewire drive, set the disk cache to the main drive.
if you are still having problems with ae crashing when it reaches the max ram cache limit that you set, then you may want to use the secret pref to force ae to purge the ram regularly. take note where the render is failing (the frame number where is crashes). then hold the shift key and choose preferences (pick any preference). when the preference window opens, click the drop down menu to choose a preference and at the bottom you should see a choice called secret. select that, and set the ‘purge every xx frames’ value to a value less than the frame number that the render crashes at.. so if the render failed at frame 132, then try a value of 120 or 100. what this does is force ae to clear the ram cache at a specified frame number, rather than when the cache gets full, and that often helps in this situation.
Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW