Someone uses Autocad 2012 (2D and 3D) on modern ultrabook? It's possible use Autocad with fluent performance on ultrabook? I want to buy an ultrabook and I don't know if I can use Autocad 2D and 3D correctly. If someone has an ultrabook and uses Autocad normally, can help me on the choice of ultrabook model? Which are the basic requirements that ultrabook must have? Thank you!