Overclocking DSP to 600 MHz is basically allowing it to go to such frequency, not locking to it. As long as high enough voltage is applied (set up in overclocking profile) things should run fine. The actual frequency on which DSP runs is decided by its own "os" (baseimage.dof) according to current content/load.

I think we all agree that 720p playback on n900 is on it early stages, sure there is more to discover.

And have in mind that 600 MHz is needed only when playing high resolution/profile/bitrate movies, so an inteligent media player should set up DSP max frequency (and voltages) based on the current movie. We still lack this feature, but OMP should be able to do the job one day.

@Estel - maybe you've missed it , but there is link to 1024x720 video in one of my earlier posts, recorded with my n900.