By default, Adobe Premiere Pro renders video using the maximum number of available processors, up to 16. However, some sequences, such as those containing high-resolution source video or still images, require large amounts of memory for the simultaneous rendering of multiple frames. These can force Adobe Premiere Pro to abort rendering and to give a Low Memory Warning alert. In these cases, you can maximize the available memory by changing the rendering optimization preference from Performance to Memory. Change this preference back to Performance when rendering no longer requires memory optimization.