Turn Off App Nap

App Nap is a new feature in Mavericks that takes away processor power from apps that are in the background, preserving battery life and giving more power to the apps you are actively using. But sometimes you want apps to do things in the background, like processing data or rendering video. If you ever need to turn off App Nap for an app, just select it from your Applications folder, use Command+I to bring up information about the app, and then check Prevent App Nap. The option only appears if the app can nap.