CPU Problem
 

I recently upgraded to 10.3.2 and Protools 6.4 and everything is running fine but I went to an older session to play it back I had major CPU problems. I'm already at 1024 and 85% in the playback engine. I can't get this song to play without shutting down. It only has around thirteen tracks and a lot of pluggins but it used to playback fine before I upgraded. I've also added three or four new programs on my computer but I still have plenty of memory. Anyone have any suggestions?

Thank you