A nice external screen can take care of that. I'm a mechanical engineer myself and sometimes I have to work with AutoCAD (shudders, I hate having to work with it, too primitive). The only times where AutoCAD gets demanding is with very large files with many, many layers. Things like the layout of a plant or a building with all spaces represented.
For basic stuff, AutoCAD is just 2D lines, so it's not all that taxing.
This is what baffles me about AutoCAD; it IS just 2D lines, yet it utilizes most of my resources to do this. Even just AutoCAD open with nothing drawn is draining the system in battery, CPU, and GPU. It seems like it is just an inefficient program to me...