How computationally expensive are audio busses? I know, the general answer is “it depends on the plugins,” but what I’m really asking is how much computational overhead there is for a (relatively) empty audio bus.
As mentioned in another post on this forum, I’m building an ardour project template for virtual orchestral scoring. I currently have the following, with an elaborate routing scheme (feel free to substitute “insane” for “elaborate”), generally routed from top to bottom :
- Dozens of midi tracks, one for each orchestral instrument/articulation
- 5 “sampler” busses, each having a linuxsampler plugin instance with up to 16 midi input channels and up to 32 audio output channels
- Dozens of audio busses representing orchestral sections (to control panning, stereo width, and gain for each section)
- A handful of audio busses, each having an early reflection reverb plugin instance (to give forward stage presence to woodwind and string sections)
- A single bus with a concert hall reverb plugin
I keep wondering if all of these busses are going to result in way too much load on the CPU. So far I haven’t seen any evidence of that happening; testing on a rather commodity machine with a quad-core i5 processor, my system monitor reports very low usage of each core. I haven’t filled all of my midi tracks with content, so it might just be that there isn’t much work happening yet. I still have a number of things that I would like to do with this template, but before I put more time into it, I want to make sure that it isn’t going to crash and burn.