The best resolution and proper ratio which also fills the video box on Twitch (for my bootcamped 4 y.o. MacBook Pro with 30 down / 5 up cable internet) is by keeping encoding at 480p with a rate of 1680 and the streaming at 480p with a bit rate of 1141. I backed in to the 1680 taking out the 61 used for audio, stated above. If its the middle of the night you may be able to stream at the max bit rate of 1741 for 480p also posted above. If you hit a wall, making a new user account brings the program back to life should the worst happen.