After Effects CS6 taking lots of inactive RAM

Reboot?

 

Can you please clarify "video editing"?

 

Sorry in my past experience teaching After Effects, I found a few students brave enough to edit their videos in AE and not realising its not an NLE.
Thus why its slow and such.
In your case you are doing some basic cuts to make your greenscreen work.
There is a RAM to CPU ratio setting but Im no where near my Mac Pros to check that at the moment.

 

because any time you see a little green line above your timeline, all those frames are saved to ram. When I launch a project AE takes up roughly 500MB for a big project. As soon as I start working it can quickly balloon until available ram is used up.

 

I wonder if its the greenscreen clips and what format they are?
Ive had issues with submitted clips that were h.264 and worse.
For any post work, I make sure all clips are sequential files or Uncompressed QT.
I know its overkill but I would rather crunch the colors on my own terms.
My last greenscreen project was 2 years ago using Ultimatte so I cant say how things are these days

 

Do you have the Nightflight.aep test file?
I have it and use that as a machine tester.
I have 32GB on a Mac Pro 2.93, do you want to make a comparison?

 

I am having the same issue on several machines as well. A Retina, Mid 2012 MacBook Pro 10,1 with 16GB of ram, and a iMac 12,2 Mid 2011 with 4GB of ram. Both machines are on OS X 10.8.1 and using After Effects CS 6. After a while, the "inactive" memory, or the "blue pie slice" in Activity Monitor completely fills up, everything becomes slow, and sometimes renders fail. Normally, when After Effects is using memory, the pie chart becomes yellow, which is active memory. Running the "purge" command in the Terminal.app solves the problem temporarily, but it is a big hassle to open terminal and do that every time. Especially if you add something to the render queue and walk away from the machine, only to come back and discover that this error has caused a render to fail.

 

I cant say for sure about retina but there are talks that Adobe will have some of the CS apps up to par with the new retina systems.