If you are stuck in a file, you have to wait until Carrara is back to normal operation. This may take more than 1 hour on very large objects. Then switch to gouraud mode and save it. If you don't wait, Carrara will start from the beginning, every time you load the scene. By the way, if you close the scene during the slowdown, Carrara will remain slow with any other scene until you restart it. wolfdd