Advice: forget the old notebook. 
A 4GB Rhino file? Wow, that would be extreme big, never used a file in this size. Try to use blocks where you can. If you can than use pre meshed models (NURBS converted to low poly meshes and NURBS deleted) and the display will be faster.
For example if I’m working on a 1GB file size NURBS model than I have frame rates around 1fps.
You should look for a PC with 32GB RAM or more and a good GTX card. I’m using a GTX780 6GB and it’s ok.