Hi max, well there is not really an exact one-to-one correspondence from file size to the amount of memory that the file will take up at runtime. That's because at runtime various other things need to be calculated for the display like display meshes. Display meshes on tightly curved surfaces take up more memory at runtime than flat surfaces.

So if you're concerned about it, you would want to go into Task Manager and see how much memory MoI.exe is taking up, if that gets up to around 3GB then that's when you should start to try to separate things out into different projects.

You are probably a long ways from that with a 70MB file though, especially if it's mostly line data that probably isn't going to be consuming a lot of extra stuff for display purposes.

- Michael