well, it was never a performance demo
![pfft pfft](images/smilies/pfft.gif)
Also you're not meant to fly in it.
I'd say that memory usage is normal.
I'm guessing it's loading all the meshes and textures in view, which is everything!
That's why we have a draw distance and fog to work within the limits of ram
In your game, is it in a particular area?
Is it a wide open space with a lot of meshes and textures?
You can do a few things, ie try braking up the world into something like zones/areas (not too small but not too big, ie 1/4 of a level) then test if the whole area is in view, if not, the whole zone doesn't go to GPU maybe removed from GPU ram also.
If your level needs a high draw distance, then you'll need to swap out your high res-models/textures with lower ones and swap them back when the camera gets closer.
But if memory is your problem then you'll need to find a more optimised way of generating your models/textures, ie using code to duplicate arms/legs, swapping out colour pallets to save on textures and other fun things :(
You'll need to read the memory section on the wiki, see how 3D objects are handled:
http://www.esenthel.com/wiki/index.php?t...Containers
Also, at your stage you should be profiling GPU/CPU speeds and GPU/System ram.. not really sure how tho