I would actually set it to "auto". This doesn’t force the output to always be 24fps. It allows the player to output 24fps signals when you play a blu ray that is authored in 24fps format. Other formats, such as 60hz frame rates, will not be changed. The 24fps will allow movies to be shown in their more natural format. The reason to turn 24fps off is when you have a display device that has a problem with 24hz frame rates. The "auto" feature should automatically determine this through hdmi.