What is it that you are really trying to do? Else we are basically throwing rocks at “Here is my totally unoptimized and completely unrealistic scene, why is it slow?”
Instead, how about we talk about what effect you are trying to achieve and suggest ways of making that feasible. As it is, you are rendering 75% of stuff that can’t even be seen and you are rebatching every frame… both of which are kind of crazy.
Geforce 7800 processing 1100 Millions vertices/second. That should be enough for 1100 /14 = 78 fps, theoretically maximum. It is not released today…
And if you got a good sample of a 780 you can render 275000000 vertices per frame. Who cares. That are just theoretical maximums… you will not get even close to this number.
The fact that i cannot see 14m vertices in your scene suggest that you render lots of useless stuff.
This is the grid in “MonkeyBlaster”. I want to optimize performance. As you can see performance of this code some like in scene with 200 000 boxes. Grid was created on two screens 1600x900 from box meshes. I’m lazy to create one mesh in 3D editor, maybe exist the way to combine all meshes in one programmatically, in fact already have the code for grid creates.
Box worlds are not made out of boxes!! The mesh in minecraft is only the surface of those boxes and gets recreated/changed when the user removes or adds what he thinks is a “box”. Search the forum for “voxels” or simply use the “cubes” plugin.
So don’t stack boxes.
Just create the mesh manually like every voxel engine does. Don’t batch single meshes, make one mesh and modify that.
Just stop ignoring the obvious 
In your simulation do the proper math with as little data as possible, then update the vertices for the single mesh. Do not create many meshes and many geometries. This is plain wrong. In your example pictures there are no boxes. There are mathematical points (not boxes) which are visually dispalyed as boxes. All this is better handled directly, first - point positions and then - box vertex positions.
Heh, you could even draw the “boxes” in a shader from a set of points… this way even not so cool Geforce 7800, but a video card 5 years old could render them with a much higher FPS… because even with Geforce 7800 power is meant to be put at use and not wasted on vanity…
This may help Let’s Make a Voxel Engine I read this but never really wanted to make a Infiniminer clone.
