How to Optimize Real-Time Performance in Csound for Live Electronic Music?

General
#1

Hey guys… :innocent:

I am new to Csound and have been experimenting with it for creating live electronic music performances. I have managed to build some basic instruments and effects and I am really enjoying the flexibility and depth that Csound offers. However, I have been facing some challenges when it comes to optimizing the real-time performance.

My current setup includes a laptop running Ubuntu with 16GB of RAM and a quad-core i7 processor. I’m using Csound along with a MIDI controller to trigger various synths and effects in real-time. I’ve noticed that when I start adding more complex instruments or multiple layers of sound processing, I get occasional audio glitches, latency issues, and sometimes even CPU overloads, which are quite frustrating during live sets.

I’ve read that there are several ways to optimize Csound for better real-time performance, but I’m not quite sure where to start. Here are a few specific questions I have:

  • Are there certain opcodes that are known to be more CPU-intensive than others? Should I be avoiding certain ones in real-time contexts? If so, are there any recommended alternatives or best practices for optimizing these?

  • What are the key command-line flags or settings that I should be aware of for improving real-time performance? For example, I’ve seen mentions of using -b and -B flags, but I’m not entirely clear on how to adjust these for optimal results. Any advice on this?

  • How do I determine the best buffer size for my setup? Is there a general rule of thumb for balancing buffer size and latency in Csound, especially for live performance?

  • Are there any specific tweaks or configurations on the OS level (like CPU governor settings, JACK settings, etc.) that I should consider to get the most out of Csound?

I also check this: https://forum.csound.com/t/csound-max-object-not-working-in-a-max-for-live-instrumentqlik But I have not found any solution. Could anyone guide me about this?

Thanks in advance!

Respected community member!

#2

Hi!

The things you can try:
Are you using Jack?

  • if the xruns happen in Jack (you should see it in qjackctl) - increase the buffer of jack. Normally 256 should be fine, you might try with 512 but that gives noticable latency.
  • if there is no xruns in jack but only in Csound console
  • try to increase ksmps - this less likely to help
  • increase -b and -B ; start with -b256 -B1024 and then make them bigger (as powers of two), firt play with -b, that is Csound’s internal buffer. Again, it adds latency.

But you are right, it may be something in your code, especially since you mention CPU overload that should be rarely the case with i7 CPU. Most CPU extensive things are spectral processing (FFT opcodes), convolution to mention some, but there might be something in your code that is not right, for example you create too many instrument instances in the same time, recreate a large table on every event, large loops on every k-cycle or something else. Can you share your csd?

Greetings,
tarmo

Kontakt Chitra Mishra via The Csound Community (<noreply@forum.csound.com>) kirjutas kuupäeval R, 30. august 2024 kell 09:35: