Program is eating up memory...for what?

I just ran into another problem:

After i was done with the heighfield/texturin/viewport manipulation code etc, i recognized, that the program seems to use ~50 MB(!) when it’s started, but the Win2K tasklist shows it uses 17 MB. Now when loading textures or heightmap files the memory increases steadily with each load procedure, but i think it should always be the same, since i overwrite the old textures and also delete the displaylist(s) before recreating them.

Has anyone experienced this too?
Where does it come from? And why does the application use 50 MB of RAM anyways while it displays 17 MB in the tasklist?
Could that have something to do with the way i’m displaying the openGL rendering (i’m quite new to OpenGL, so i used the standard(?) rendering methods described at http://devcentral.iftech.com/learning/tutorials/mfc-win32/opengl/ tutorials. Is there another way to handle the rendering output? Or can the method from the tutorial be optimized?

I use the following default scene stats:
Heightfield image: grayscale 1024x1024
Heightfield texture: RGB 1024x1024
Heightfield geometry: triangle strips with 256x256 steps.

(I freed all memory used for heightfield/normals generation already, no change with the problem).

Any help is greatly appreciated.

[This message has been edited by iLLuminatus (edited 02-16-2001).]

Display lists can use very much memory. I have a program where I can choose between display lists and vertex arrays. Display lists ~ 250 MB!!! vertex arrays < 20 MB.
The solution for me is not to use display lists, because I just cant accept that a mesh consisting of ~11000 triangles takes up 250 MB memory.

-Lev

Thank you so much for that hint!
Can you possibly point me to an easy understandable tutorial on vertex arrays?