Engineering workstation that also is good for gaming?

I am an architect (designer of buildings) but I also like gaming. I am wondering has anyone heard of a computer that does both? I have read most of the discussions of engineering workstations vs. gaming computers and I am finding that the graphics cards are more or less mutually exclusive. I know I must spend a huge amount of $ on an engineering workstation but is it possible to get both gaming and workstation graphics cards installed that just have a switch for using one or the other...or is it more complicated than that?