Hi @jeanette ,

First, I would like to know what specific modification of iMac 27" do you want to purchase?

My recommendation is to start with 3.3GHz 6-Core Processor model with at least 512GB Storage and 16 gb RAM.

This modification will allow you to use both AutoCAD for Mac - as native app and AutoCAD for Windows - inside Parallels Desktop Virtual machine.

The performance of such a model is enough for fast and smooth work with large DWG files in AutoCAD (Mac and Windows versions) and with raster images in Photoshop.