Windows Display Driver Model

Windows Display Driver Model (WDDM) is the new Microsoft way of displaying things, Here is how it works, In older versions of windows a window used to draw its contents on the screen whenever it (or part of it) is visible, Now the last outputted content of that window is stored by Windows, so that the window does not need to redraw every time it gets visible, Also when an application crashes it will not be erasing like in previous windows of windows, Now to you this might look more efficient, I would have to agree that it is nicer, but more efficient, i'm not so sure about that.

More memory is needed to cache the windows, Also, the graphics card capability needed is many many folds that needed for previous versions !

The AERO interface built on WDDM uses Direct 3D in your graphics card, this is the part of the graphics card that was never utilized by windows before, It was more like the part game manufacturers uses, Now windows focuses allot on looks, so it is only expected they would start using it for the OS itself, But it is again not like Microsoft calls it (GroundBreaking), the technology has been used for a long long time (by game manufacturers).

WDDM 1.0 (currently shipped with Vista can make use of the advanced hardware on the market now, WDDM 2.0 should have more features, but will require a new generation of GPU's