Thanks for the replies. I think I will continue with my current setup. I don't think I can add more memory- the slots are full/unless I upgrade Motherboard. I may try to upgrade to a dedicated video card...I have 2 free PCI slots. Thanks again you two.

I have an HP Pavilion 512w (2002); celeron, 8GB free space on HD, 512RAM, Intel integrated graphics (down). I use AutoCAD 2004. CAD works fine if the files are small (I program a Biesse CNC). SU is slow when viewing large models (files). What is the bare minimum system required to view larger files (7 MB is large to me).