I am running PhotoScan standard 0.9.0 on a 8 core Windows Vista computer without using a GPU. Often I want PhotoScan to work in the background while I am doing other work on the same PC, so it is not good if PhotoScan uses all 8 cores. I tried to de-activate some CPU cores (under "preferences"), but PhotoScan still uses all 8 cores. Is there a way to free some CPU cores?