Slightly tangential: I prefer Superfly 'progressive' as I can quickly see if scene will 'work'. Also, same results on this CAD Tower's twin GPU cards, its CPU-only, or networked 'Box' CPU-only...

(#1 is fast within now-ageing cards' complexity limits. #2 is reliable but, even as 'background', slows PC. #3 is 'Whoosh'...)