DSP/CPU level

Hi everyone,
I’ve just downloaded the demo for Ardour 5.9, it looks like a fantastic DAW that could work really well for me. But I’m getting some extremely high DSP usage with only a single audio track looping a short drum loop. With no plugins and the Buffer Size set to 512 samples the DSP meter is over 50% and frequently hits 90%+. I’m getting audio dropouts and the loop doesn’t repeat perfectly (getting a slight delay every time the playhead loops back). Upping the buffer size helped a little but in Max/Logic/Ableton I can easily run multiple tracks/plugins with buffer size 128. Running a Mac Core 2 Duo 2.53GHz from 2009 so it’s not the fastest machine these days, but considering it handles other DAWs fine I’m wondering if I’ve set up something wrong? I have selected “all available processors” under DSP CPU utilization but not a lot of improvement…

I understand from the documentation that I shouldn’t expect Ardour to necessarily match commercial software in capabilities but this seems pretty unusable at the moment. Otherwise the feature set looks amazing so I’m really hoping to get it running properly!

If I’ve missed something really obvious I apologise in advance.


Hmm doesn’t sound right no. They key might be, are you running any plugins?


Just opening an empty project the DSP usage is sitting around 50%, if I try to play 1 audio track it goes up and then when I start adding plugins it is sitting around 80-100%.

Running zero plugins at 512 buffer size and looping one short drum loop which is a WAV file 48kHz I am looking at DSP usage jumping around between 30% and 100% while Ardour CPU% in Activity Monitor is around 25-30%. In other DAWs both of these figures would be single digits in this situation!

Any help would be much appreciated!

I’m not really a Mac user (so this might all be out of date now) but at one time there were issues with CPU usage. Select Window->Preferences->Show->General. Try changing the DSP CPU Utilization. You’d imagine that using more cores would improve things. But for older Macs (at least, for Mixbus) I think they often worked better if you selected just 1 core.

Remember that any changes will only take effect next time you restart Ardour.

Also experiencing heavy CPU usage here, version 6.0 in OSX (compiled full version).

Around 20-30% usage in standby, 4 waveforms, no playback. When adding VSTs it reaches 95% easily.

The Pearl is perfect otherwise.