How OpenGL manage it's Video Memory

My program consume much video memory(>100M) to store many textures,so I want to know if the display card has not much video memory,what will happend?Is there a mechanism in OpenGL driver like the “virtual memory” in OS?

It is driver dependent, as opengl does’t specify any behavior in this case(at least none I know of)

But it is most probable that the driver will use your system memory to unload the video memory. You still shouldn’tupload more data then you need