Making it understandable here is a sample of a render made in Poser 13.0.339 using the Volume feature for a fogy cloudy atmosphere. The render took 1min 34sec 2000 x 1080.... Poser 13.1 up would take almost an hour rendering the same setup if you cancle the render in P 13.1 it takes 2 min not like in P 13.0.339 in just a second, You also experience a Pc hang if trying to render Volume effects in Poser 13.1 up

Rendered using the Volume feature in Poser 13.0.339 .... not possible anymore since Poser 13.1 up