Made a test to be sure using the CPU instead of GPU High setup on Poser 13.0.339.0 and Poser 13.1.518 for about 40 sec render excluding a GPU Bug

Poser 13.1.518 made 2 samples in 44 seconds a fan liftoff and overheating of CPU

Poser 13.0.339 made 86 samples in 40 seconds CPU says cool no fan liftoff

this means that the new releases take over 40 times longer to render then the old version before 13.1 if using Volumes in combination with 3D textures, worst case would be globally using 3D textures. Not a GPU Bug for sure now. The test was made just with a Simple Cube as Cloud carrier no other stuff loaded. CPU and GPU show a a major slowdown on P13.1 up ....

@Rhia474 Yes would be nice to see if or how many others having the same issues .... 

@Sunfire as soon as it is confirmed not to be just my issue then will send them the link to this thread ....