DSP Ramping up to 100%, Then Audio Distortion, Breakdown in Signal

I don’t know how many tracks I have laid down, likely 50 or more, composing a piece, and adding percussion last night, brought me to see that red alert of DSP percentage amping up in the right top corner of Ardour.

Is there something I can do to get my 2010 Mac Pro (with full capacity RAM for it’s specs) to take on some of that load of processing? Is a new or better sound card a way to solve this, or other hardware?

Thanks much for helping me grasp solutions, so as to continue with this computer and be able to continue adding tracks, and have this hardware (sound card) be able to handle it all.

This is mostly CPU bound. You can try to increase the buffer-size (Menu > Window > Audio/MIDI Setup) try 1024 or 2048, or see if perhaps some plugin requires a lot of CPU time (Window > Plugin DSP Load).

Thanks for that. I was at 1024 buffer size, moved it to 2048, then for whatever reason, as I tried to process some “loudness analysis” the audio signal just went to garbage. Things went back a little normal when I went back to 1024.

A minute ago, my computer just shut down and rebooted, saying it had a problem. I’ve never seen it do that before.

I opened up the “Activity Monitor” within the Mac OS, and it was listing 300-400% of CPU usage while I had Ardour playing. Wow. I don’t recall seeing that much processing need with anything ever, including Final Cut Pro or the very systems intensive Adobe After Effects. Those plugins sound amazing, but they take a toll.

Screen Shot 2023-03-17 at 9.25.56 PM

The “Plugin DSP Load” window reveals a good number of instruments listed into the red range.

Spitfire Audio’s BBC Symphony plugin with the “Mandolin” applied to a track in the mix was for sure a giant sucker of processing power, I believe.

I realize I’m on a Mac that is 13 years old, which at the time of purchase was very pricey, and very powerful, and which for so many applications and software it should continue to work great (the stand alone Adobe Suite software, for example, that needs no monthly subscription is nice).

Seeing the restrictions I’m coming at with all of this music composing magic, I’m now getting curious as to what a 13 year old newer CPU would truly manifest in a Mac computer, by contrast to this one I’m on. I hardly want to think of it. What a pricetag my ideal upgrade would be. Maybe when I’m making some money with music, I can justify such an investment.

If synthesizer plugins are causing heavy CPU usage you can have the MIDI track rendered to audio, then stop the synthesizer processing. I forget the menu option, and I am not near my computer to check, but I think it is something like freeze track.

I’ve seen that menu option before. I’ll perhaps get on that soon.

What is crazy, is I exported a clip and it was playing earlier in a loop. Now, it can’t play without major distortion. I’ve been shutting down programs, the CPU seems to not be taxed, but just playing that file in Quicktime, now, renders it immensely distorted. I’m baffled by it. It’s not an Ardour problem, it would not seem.

I think I’ll reboot the computer to see if that gets rid of this horrible choppy audio that seems now to infect everything I play.

EDIT: I rebooted, and now the files I exported out are playing without distortion.

Second EDIT Update: A few more hours and the crackling audio returned. I swapped the USB connection to my VOLT audio interface and that solved things.

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