Depends on what it's gonna be used for. The high res doesn't stress your video card at all really unless you're running demanding 3d accelerated apps like games. Dunno if autocad uses 3d acceleration like 3dsmax does, but if it does I can't imagine it's very demanding on a 3d card.
If you wanna play F.E.A.R. on them at 1680 x 1050 however, that's a different matter entirely. That would take a near top-end PC.