This is a rather convoluted question but I’m at a loss and am hoping someone here has come across a similar issue.
I’m using a VST3 plugin (not instrument) to receive, alter and forward on MIDI data to an instrument track.
What I’m running into is that the VST3 (despite doing very simple things) seems to overload the CPU when too many MIDI notes are transmitted this way. Even when the VST3 itself is bypassed(!!) Cubase still insists that there is a huge CPU load on it.
Curiously, I can control the CPU load based on the amount of polyphony I send to the VST3 for processing; almost as if things build up in a feedback loop way and then calm down again as I send it fewer notes. I’m not talking 80 notes here, basic triad polyphony overloads it.
The minute I re-route without the VST3 plugin that alters the MIDI data everything returns to normal and the CPU load is basically zero.
This occurs with ASIO Guard on or off, high or low, whether I route or MIDI send etc etc.
It sounds very much to me as if this MIDI altering plugin is the perpetrator here. Or is this a trick question?
I would contact the maker of the plugin.
I agree, but the developer has been very helpful and even provided a pluginval showing how thoroughly it passes everything. The plugin works well in Studio One and Reaper.
Turns out that when I do a preferences reset on Cubase 12 everything works correctly on the first clean startup. Then, without changing anything preferences related, if I close the fresh Cubase 12 and reload it, the problem occurs again.
You haven’t got it sending from track A to B and then B is also feeding back into A or anything odd like that? i.e. unknowingly created a feedback loop.
I’d put MIDI Monitors on both those tracks and watch the data come through.
Right? I think that’s a great point and I checked but no, nothing is looping back AFAIK.
Any thoughts on why this would occur:
Turns out that when I do a preferences reset on Cubase 12 everything works correctly on the first clean startup. Then, without changing anything preferences related, if I close the fresh Cubase 12 and reload it, the problem occurs again.
That one really stumps me. It’s almost as if something is happening on close that makes this occur. Also note that this restart issue doesn’t happen in 11.
There was recently an update released (12.0.51) which has caused some strange issues elsewhere in the software.
Also what VST is it? Some plugins can trigger a background service and it’s possible that isn’t shutting down between sessions. I’ve seen that occur with some of the online music theory generative plugins before.
Forgot the name of the one I tried now, but it’s like an online “always connected” service and that would cause performance issues after I’d used it for a while.
I’ve tried it now on 12.0.3 as well as the latest update.
I will ask about background services and shutdown. It definitely seems like something is changing when I close a freshly cleaned Cubase that then prevents the VST from working properly.
Like I said, this behavior doesn’t happen in Cubase 11 which makes me think Cubase 12 might be the issue.
