I am using a brand new Mac Book Pro (2.7 GHz i7; 16 GB RAM NVIDIA GeForce GT 650M 1024 MB). I am in AE 11.0.0378 (CS6). It is very very slow. Every few seconds I get the yellow loading bar even when the playhead is sitting over a solid with a basic shape, not even playing. When I try preview render I get a warning that AE "needs at least two frames for playback." I've set up my multiprocessor to render multiple frames simultaneously and allocated as many gigs of RAM as possible to AE. This is strange.
When I go to "About After Effect" I see "4% used of 16gb"
Any guidance here?
For one thing, update your AE. It should be 11.0.2.
As Szalam says, the 11.0.2 update works around a bug in Mac OSX memory management. Install it.
> When I go to "About After Effect" I see "4% used of 16gb"
That is not telling you anything useful. That's just how much RAM the foreground application is using; it doesn't include how much RAM the background rendering processes are using.
See this page for information about memory and improving performance in After Effects: http://adobe.ly/dC0MdR