Radical variations in performance

[LittleJJ]

Sometimes I can run 30 tracks with 60 or more plugins, 4-6 VIs, etc just fine. Sometimes a few stereo tracks with no plugins will pin the Processing meter.
I was recently having problems playing back a rather simple project. THe project had been around for a while and suddenly--for no apparent reason---- started pinning the Processing meter and stuttering. I printed the VI tracks: no help; printed tracks to remove plugins: no help; finally got the project down to about 10 tracks with no plugins: no help. I merged all soundbites, NOTHING helped. SO I decided to assume there was a corrupt audio file on a hunch. Deleted one track from the project, no improvement. Deleted another track, BINGO problem completely solved, Processing reporting about 5% usage at most. BUt get this! I created a new track and dragged the soundbite back in and everything was fine. SO it was NOT the audio file (soundbite) that was causing the problem, but the track itself, which is actually nothing but a visual representation in the GUI of an edit decision list. It makes NO sense whatsoever but the facts are exactly as stated. Anyone have a similar experience or a theory? THANKS

[MIDI Life Crisis]

I would first suspect a SYSEX message(s) got into the track, but other than that, I got nothin'

[mikehalloran]

Based on what you report, not a clue. We don't even know what version of DP or the OS.

[LittleJJ]

I would first suspect a SYSEX message(s) got into the track, but other than that, I got nothin'

I can't imagine how a SYSEX message would get into an audio track

[LittleJJ]

Yosemite, last. DP 9.1, latest. 12-core 3.46GHz Mac with 64GB RAM, SSDs, APOLLO interface...