Pymol Ray Tracing without wasting time

I often use the nice built in ‘ray’ raytracer in Pymol. These ray traces can take minutes to hours, and during that time I of course want to use my computer! Unfortunately, the Pymol window freezes during the ray trace, so when I switch virtual desktops it sometimes looks as if there’s a frozen terminal or similar there, which I click on, sometimes inadvertently, sometimes because I am a fool. This click gets queued up to Pymol and promptly delivered as the ray trace finishes - making the window redraw with the built in opengl, wasting all the time ray tracing, arg!