Choppy Performance / Playback in 15b6?

I have just upgraded to b6 from b5.
In the same project that I was working on, the playback as well as timeline scrubbing, suddenly seems very jerky. Its almost as if the CPU is being taxed and it is waiting for it to catch up. I've opened the resource monitor on Windows 10, and when scrubbing the timeline the CPU usage is at about 20-25%. I don't remember what it was in b5, but in b5 everything was completely smooth using the same setup and same media, project, etc..
Has anyone else experienced performance issues in b6?
In the same project that I was working on, the playback as well as timeline scrubbing, suddenly seems very jerky. Its almost as if the CPU is being taxed and it is waiting for it to catch up. I've opened the resource monitor on Windows 10, and when scrubbing the timeline the CPU usage is at about 20-25%. I don't remember what it was in b5, but in b5 everything was completely smooth using the same setup and same media, project, etc..
Has anyone else experienced performance issues in b6?