What does 'Optimize for Video' actually do?
 

Does this setting increase the bandwidth assigned for video giving better performance in general, or does it do something more specific like change the compression algorithm to something more suited to video playback??

Also - what count's as video? Are we talking specifically hardware decoded MPEG streams or anything that involves moving images in general?

Thanks!

It lowers the quality of full screen video to try and maintain a high frame rate. However the software will only do this if it cannot keep up with the video frames. Therefore on higher end systems, you may see no difference if this option is enabled or disabled.

Wim