Author Topic: Lots of VSTs cause system stall  (Read 265 times)

Offline Svenni

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Lots of VSTs cause system stall
« on: December 13, 2019, 22:46:10 »
Does openmpt open every single vst whenever you do something in the program?

Cause i have a lot of vsts on one song and even just playing a sample without any vst on it, stalls the entire computer for quite awhile.


Offline Saga Musix

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Re: vst question.
« Reply #1 on: December 13, 2019, 22:57:37 »
Every plugin that is loaded into your song can potentially cause output at any point in time (even if you don't feed any notes into it), so yes, having lots of plugin loaded at the same time can cause a significant slow-down. Plugins are just arbitrary pieces of code that OpenMPT has pretty much no control over, so if they are badly written, they could potentially consume a lot of CPU without doing anything useful. Especially if their editor window is open, even more CPU time is being consumed. If the machine has low specs (too little RAM for example) this can make things even worse.
Try removing the plugins you don't need, or at least bypass them. It may help.

If the above is not possible, there is also an experimental hidden settings "EnableAutoSuspend" that you can try setting to 1. When doing so, OpenMPT will check if a plugin has no active input and automatically suspend its output after a few seconds. This setting will only apply after reopening your song.

Edit: This kind of questions go into the Help and Questions forum. The development forum is just for asking about questions related to the OpenMPT source code or tracker development in general
« Last Edit: December 13, 2019, 23:23:24 by Saga Musix »
» No support, bug reports, feature requests via private messages - they will not be answered. Use the forums and the issue tracker so that everyone can benefit from your post.

Offline LPChip

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Re: Lots of VSTs cause system stall
« Reply #2 on: December 14, 2019, 11:43:32 »
Quick question from my end. If you set a plugin to bypass from OpenMPT (not using the plugin itself if it supports it), am I correct that it does not consume any CPU usage at that time unless you have the plugin open, or can it still consume CPU time if its coded poorly?
"Heh, maybe I should've joined the compo only because it would've meant I wouldn't have had to worry about a damn EQ or compressor for a change. " - Atlantis
"yes.. I think in this case it was wishful thinking: MPT is makng my life hard so it must be wrong" - Rewbs

Offline Saga Musix

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Re: Lots of VSTs cause system stall
« Reply #3 on: December 14, 2019, 11:50:00 »
No, there is no such guarantee. Bypass only prevents the audio processing function of the plugin from being called by OpenMPT. OpenMPT also tells the plugin that it is now suspended but I have no idea how many plugins make use of this information. If the plugin has any additional background threads that are constantly running, OpenMPT (or any other host) cannot prevent them from running.
Strictly speaking, if you put some effort into it, you could write a plugin that keeps consuming resources even after unloading it from OpenMPT, but I would believe that no widespread plugin does that.
» No support, bug reports, feature requests via private messages - they will not be answered. Use the forums and the issue tracker so that everyone can benefit from your post.

Offline LPChip

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Re: Lots of VSTs cause system stall
« Reply #4 on: December 14, 2019, 14:21:46 »
Cool Idea, I'll make this awesome plugin and put a cryptominer in it. :nuts:

No, just kidding. If I could code this, I would already have made quite a few plugins. :D
"Heh, maybe I should've joined the compo only because it would've meant I wouldn't have had to worry about a damn EQ or compressor for a change. " - Atlantis
"yes.. I think in this case it was wishful thinking: MPT is makng my life hard so it must be wrong" - Rewbs

Offline Svenni

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Re: Lots of VSTs cause system stall
« Reply #5 on: December 16, 2019, 04:59:14 »
Thanks.