What is the difference between "Sony BDP (NTSC)" and "Sony BDP (NTSC, No DivX)"?

I can't see a difference, but then I don't understand what's going on "under the hood" of Mezzmo. Will the former transcode faster/more efficiently? I am always trying to tweak a little more performance out of my PC.

I am using a Sony BDP-BX57 for play back.

Thanks,
Mark L.