Thank you for your reply. Yes I know that option, it's flagged, and I also tried the settings in Option/General/Video Crd. I made several tests in the last days trying MadVR and its algorythms, my system actually it's not up the madVR. So I bought (still waiting for delivery) an ASUS GTX 650 Ti , mainly because I will use madvr for loading in it a 3dlut for charactarization of my projector.
While making all these tests, I decided to install MC19, and it was then that my problems started... Even setting RO Standard, the stuttering is overwhelming! Cpu is always above 60%, and tools for gpu usage indicates always 0%!
Actually the only solution is to uninstall MC19, deleting folders that strangely don't get deleted by the uninstallation process, fresh install of MC 18 and importof the library backedup without importing the settings.
Have you a better idea before I abandon this MC 19, since I suspect that there's a bug somewhere about the usage of the gpu....