Subtle audio glitches

1

Hello,
After having successfully done many gigs with “songs” containing spefically plugins/racks that are needed there, I’m starting to build generic songs that will typically contain:

  • a left-hand bass (NI Icon Bass)
  • main keyboard patch (typically NI Noire or Canterbury rhodes or some wurly library)
  • a synth layer/split (typically a Zebra or Diva pad or lead)
  • a strings layer (Virtuoso strings library)
  • a B3X split in upper octaves

Seems like a lot but it’s not all active at once - raising a midi fader would enable Routes, change split points and change Gain for those plugins. BUT all of them need to be running in idle without any active midi routes to prevent glitching and delays during plugin/rack enabling.

The PC should be fine with this - DeskMini B760 with I5-12600K.
And in practice, CPU usage is practically non-existent, and time load under normal conditions in this setup never exceeds more than 50%, normal would be more like 25-30%.

HOWEVER - sometimes I only press and hold a 2-3 notes and suddenly a subtle glitch is heard after some time - sometimes I get a very short (only 1 bar in the profiler) unexpected time load around/over 100% and during this temporary increase profiler reveals much increased time load in MOST plugins there, not a single one. And sometimes there is a glitch heard even with time load around 50%. It’s a subtle and short glitch and RME doesn’t even register the glitch in their settings tray app. It’s not the usual buffering issue.

I’ve paid attention to following settings:

  • High performance plan
  • disabled C-states in UEFI
  • set cantabile multicore support to number of physical cores (P+E) minus 1
  • set affinity for cantabile.exe to only occupy physical cores (P+E seems better than only P though)
  • set Kontakt to use a single core (or two cores max, not much of difference)
  • speedstep/speedshift and hyperthreading left enabled because otherwise it was worse.
  • LatencyMon doesn’t reveal anything, all green there
  • cpu usage under load is about 4% and there are no visible spikes in task manager/“process explorer” when the glitches occur
  • no thermal throttling, CPU temperatures always around 60°, maybe 70° under more load

So by the usual metrics everything should be running fine and I’m quite frustrated beacuse I lack deeper knowledge about finding such culprits. To me it looks like either a plugin misbehaving even if only running in idle or there is a deeper system issue. But in neither case I can’t seem to find anything obvious.

Any idea where to look next?
Thanks and regards,
Matej

2

I would try running Process Lasso on the box to optimize it. The product does hardware level optimizations specific to cpu class that Windows Power Plan and application optimization options don’t reach. They have a demo, to optimize right click Cantabile.exe and do “induce performance mode” and it will configure itself. Also, you can try setting affinity specific to Cantabile inside PL for P core only, but tbh it may actually run better with all cores + hyperthread enabled. Costs a bit of your time to try it, but if it still doesn’t work right with this, it has nothing to do with hardware optimizations.

1 Like
3

+1 for Project Lasso. I bought the multiple computer license and find it’s helpful for many situations. Very reasonably priced.

4

Hi,
Well I forgot to add that I do have Process Lasso and did those optimizations. But based on your posts I revisited the settings there and I found that somehow affinity for cantabile somehow got expanded to all cores - including virtual ones which shouldn’t be there!

I immediately disabled hyperthreading there (for cantabile.exe only) and quick tests look positive!

Will do some more stress testing but looks promising now!

Thanks and regards,
Matej

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5

What else is running? I ask as a web browser idling can cause the odd glitch with home audio interface. Looks like you use RME so not a problem there, assuming you’re using ASIO?

Don’t know virtuoso, sounds like sample-based. Is that loading/unloading? Likewise for piano library. Not the question you asked, but Pianoteq is better - fast to load, and sounds great particularly in a live context.