RAM issues with AE

After Effects will only use as much RAM as it needed to render the frame.  Having more than that allows for longer Previews and minimizes out of memory errors, but doesn't make it faster (that would be processor speed).

When you say rendering do you mean rendering, or do you mean previewing?

Without any exact details about the project and more precise system info none of that means anything. You could simply be using features and effects that are fully hardware accelerated and AE is just breezing through, not needing to cache to RAM. That being the case, unless you experience issues liek the render time being extremely long or content not rendering there is very likely nothing to worry about. and of course you can test this hypothesis easily by creating a reasonably complex project (or downloading one) and observing the differences in behavior. Otherwise simply more info is needed to determine if something is wrong.

Mylenium