[jdowdell]

True on the framerate -- it's an upper gate. Static video which overburdens a configuration can drop frames to keep up. But interactive presentations need to display each intended frame, and so will drop framerate instead. More here: http://www.kaourantin.net/2006/05/frame-rates-in-flash-playe...

For the "why", that's Adobe Corp's tale to tell, but I haven't yet met a person inside Adobe who wouldn't be very, very happy if Mac/Win performance differences could be made to disappear.

[RWilson]

That's a great link, I had not seen that article before. Though, in practice,the actual framerate to vary from the specified by much more than the -10 / +5 fps that he lists.

His final sentences might be relevant to this topic:

On high CPU load we might actually cut [the max framerate] into half, e.g. 30 frames/sec. OS X already does this in certain conditions.

Wish he had expanded on that a little more. Any idea what conditions cause OS X to halve the framerate?