Percentage of RAM used

Hi all

I have been playing around with memory settings for AE CS5.5 and taking some advice from here:

blogs.adobe.com/toddkopriva/2010/10/please-try-recommended-memory-sett ings-for-after-effects-cs5-and-give-feedback.html

and here:

http://forums.adobe.com/thread/734343?start=0&tstart=0

With variety different compositions, and different memory settings I have noticed my 'RAM: % used of 24GB' in my Render Queue window (at the bottom of the window) is always pretty low. Anything between a few % and 25% ish.

Is this just showing me the RAM used for the foreground CPU and not the collective CPUs?

Any info is much appreciated.

Cheers

A