When I set the rendering to Progressive with GPU Acceleration, the GPU doesn’t contribute to the computation. It only kicks in when set to “Interactive”
Check this thread: Vray - Rhino - GPU and CPU rendering - #4 by Marc - V-Ray - McNeel Forum
Hello, Marc,
This is a known issue. It has been resolved internally and the fix will be included as part of the v3.6 update.
For a temporary workaround, please use the file I’ve sent you in a PM.
Kind regards,
Peter