What does nonlocalVRAM do?

[TheMantis 10]

language="English";

adapter=-1;

3D_Performance=-4194304;

Resolution_Bpp=32;

Resolution_W=1920;

Resolution_H=1200;

refresh=60;

Render_W=1920;

Render_H=1200;

FSAA=0;

postFX=0;

HDRPrecision=8;

lastDeviceId="";

localVRAM=1073741824;

nonlocalVRAM=0;

I ran multiple runs through ARMA2mark and it doesn't matter what I have this set to, fps is consistent. I also ran around in the game and it seems the same.

I forced 1GB local VRAM in the .cfg file then made the file read only because ARMA2 would change it on me otherwise during initial startup.

So what exactly does nonlocalVRAM do?