Been using Ardour for years recording rehearsals, and twice now I’ve been not in my basement using it (interfaced with an x32) and was unable to get a clean recording.
The sample rate is 48KHz with 32-bit resolution. I admit I was not observing the buffer size, but presume it to be what it always has been in my basement - not doing anything realtime through my Mac, just recording and not even monitoring. IIRC, I was using an aggregate device. A new Mac Pro laptop and SSD was used w/ 16 channels. It is sure hard to keep an eye on everything when at a venue. What is frustrating is that the first 20 minutes during setup I checked playback and it was fine. Routinely use a Hackintosh with HDDs that is years old w/o any troubles.
The capture buffer looked fine, and for over three hours only one xrun was marked.
This is what was recorded after about 20 minutes (verified by loading the interchange wav files in audacity). Maybe someone has enough experience to hear the cause?