Using VSTi's seems very slow

Started by HvitRavn, April 22, 2007, 17:57:35

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I did some investigation with SynthEdit.

Appearantly the following problem is happening:

If a plugin has a high number of polyphony, a delay becomes noticable.

I made a simple plugin with just one convertor, one osc, and one adsr, with normal settings.

I added 10 instances of it in openmpt and played one note with each of them.

Playing the song, and it was fast as it should. Direct response.

Then I changed the default polyphony from 6 to 128 and I played the same song with OpenMPT. The delay raised to about 8 ms.

Since I have a plugin that has a huge delay, I went to check it out further.

My track has 5 plugins. I changed the polyphony of 32 to 6 and saved again.

The delay went down from 35 ms to 12 ms.

I'm going to see if I can change my polyphony more in different sections.

This text is how I found out:

Quote from: "synthedit wiki"

audio paths

Anything that comes out of, or is connected to a Midi to CV is duplicated (invisibly) for the purposes of polyphony. So, if your container is set to "polyphony=6" then there may be 6 invisible copies of your signal chain.

There is an excellent item about this in the current SynthEdit manual under Tutorials & Reference/Tricks & Traps/Optimising CPU usage. This section shows some simple examples of how to reduce CPU usage by simple re-routing to avoid costly processes.

EDIT: I do doubt that this is the only problem though...
"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