WDI

jamescollins
If any Cakewalk staff members are still lurking, one of the nice things about VST3 (as far as I know, which isn't very much!) is it's ability to only consume CPU power when a clip is playing. Apparently with VST2, if there's an insert in the FX bin, it's using CPU power the whole time, even if the track only contains a clip that plays for a fraction of a second. Am I right about this? And if so, will this be one of VST3's features which will be implemented in X3?

For whatever reason this issue is always annoyingly skated over or I just don't understand the responses given. So I've come to the conclusion that there is absolutely no CPU performance improvements of VST3 over VST2.

In fact, as stated in previous threads by Cakewalk employees DXI actually implemented CPU throttling on empty tracks or where no clip was currently playing on the timeline. From my tests I've never actually witnessed this however. CPU consumed by a plugin was always constant in Sonar.

I'd love to be corrected about this issue.

VST3 silent buffer flagging is implemented in X3. There is no rocket science here - its just a flag that is passed to the plugin to tell it that it is being given silence to process and then SONAR checks the flag on the output and passes it down through out engine so it knows its a silent buffer and can skip the more costly math. We've been doing that stuff in our engine from about 1997 :) Plugins built with the DX SDK could query the buffer for an interface to check that state and take action if they wanted to. I'm not sure if any plugins took advantage of it though.
 
Afik the only VST3 plugins that may use this flag are the FabFilter ones. Waves doesn't. So just because the host implements it doesn't necessarily mean you will see an advantage. The most benefit would be for synths since they stream silence most of the time.
 

Noel Borthwick [Cakewalk]

WDI

jamescollins
If any Cakewalk staff members are still lurking, one of the nice things about VST3 (as far as I know, which isn't very much!) is it's ability to only consume CPU power when a clip is playing. Apparently with VST2, if there's an insert in the FX bin, it's using CPU power the whole time, even if the track only contains a clip that plays for a fraction of a second. Am I right about this? And if so, will this be one of VST3's features which will be implemented in X3?

For whatever reason this issue is always annoyingly skated over or I just don't understand the responses given. So I've come to the conclusion that there is absolutely no CPU performance improvements of VST3 over VST2.

In fact, as stated in previous threads by Cakewalk employees DXI actually implemented CPU throttling on empty tracks or where no clip was currently playing on the timeline. From my tests I've never actually witnessed this however. CPU consumed by a plugin was always constant in Sonar.

I'd love to be corrected about this issue.

VST3 silent buffer flagging is implemented in X3. There is no rocket science here - its just a flag that is passed to the plugin to tell it that it is being given silence to process and then SONAR checks the flag on the output and passes it down through out engine so it knows its a silent buffer and can skip the more costly math. We've been doing that stuff in our engine from about 1997 :) Plugins built with the DX SDK could query the buffer for an interface to check that state and take action if they wanted to. I'm not sure if any plugins took advantage of it though. Afik the only VST3 plugins that may use this flag are the FabFilter ones. Waves doesn't. So just because the host implements it doesn't necessarily mean you will see an advantage. The most benefit would be for synths since they stream silence most of the time. 

Thanks for the reply Noel.

I guess I was thinking the host Sonar could use the silent flag passed back by the plugin to then completely bypass the effect when it's not being utilized, like bypassing it in the effects bin or turning it off and then turning the effect back on when a clip requires the plugin for processing.

I haven't seen a host do this automatically. I know SAW Studio does allow for bypassing VST effects, or turning them off and on, in real time using an envelope and the effects are easily measurable.

That's how I was interpreting VST3 spec but it looks like it is the host that would need this functionalty.

From my experience Sonar is constant in its plugin CPU utilization regardless of a clip present or not. Even when the project is not playing the CPU utilization of a plugin appears constant. Perhaps there is a difference but its not measurable such as bypassing the plugin and the CPU utilization drops.

I'm not talking about virtual instruments but rather effects plugins.

So I guess the answer the question, does VST3 give any CPU performance benefits, the answer would be no, unless the plugin utilizes this flag and the host bypasses the plugin.

And perhaps I'm just confusing everything in which case the simpler question would be...

Are there any performance benefits from VST3?

Noel, it is unthinkable that you have not yet written a book on audio software development.

After Midnight, no X3. G'night.