I have two graphic cards on my machine. A P2000 and a 2080 ti. In the pref for both CUDA and Optix, I choose the 2080 because it has 11 gigs of vram. But Blender doesn’t use it at all. I used the watch -n0.1 nvidia-smi command to monitor the cards and it’s clear that the 2080 is inactive. I know the card is OK because it’s working with Substance.