ASIO Guard: why is this switchable on macOS?

I always understood ASIO Guard was for PC latency issues. Why does this parameter exist for macOS? I have seen posts here that require it to be turned off for Apple Silicon using VE Pro. Seems to me it always wants to be disabled for macOS.

It also needs to be disabled for the new Power House GPU audio control in MIR Pro 3D.

OT, but are you using that? Have you been able to tell much difference in CPU load?

I’m testing it now, It seems to be quite beneficial but only if ASIO Guard is OFF.

This contradicts VSL’s system requirements which says it is “not compatible with ASIO Guard OFF for Cubase/Nuendo on macOS only”. I assume this is a mistake in their system requirements. I can’t imagine why this would be different for Dorico than for Cubase.

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I’ve done some further testing with different results. Not sure that ASIO Guard does anything at all. Seems to work similarly in either case.

Still would like to know generally what utility, if any, ASIO Guard provides for macOS.

Hi @dlb, no, ASIO Guard is not only for Windows PCs but also for Macs. And it is not about latency, but about using the CPU cycles more efficiently by evening out the average CPU load of the audio engine and therefore making it less likely that you run into overload situations where audio drop outs.


Thanks, Ulf.

So I read the Cubase documentation (as there is none in the Dorico manual), and Cubase is much more granular in terms of ASIO Guard settings for individual VSTs. Dorico is all or nothing it seems. So what is one to do? Are there certain environments where you need to have it enabled/disabled? I’d like some idea of how this works and what to do.

In Dorico it is switched on by default and you should leave it like this. It is on purpose hidden away in the last corner of the preferences, so that people don’t fiddle around with it. Only in certain situations, when you experience bad performance or audio drop outs one should switch it off. This can happen e. g. when running Dorico together with VE Pro. But it all depends on the respective system and setup, so there is no general rule that you have to switch it off when running VEPro.

OK, thanks, I use VE Pro exclusively for projects with more than 1 instrument. I also do all the mixing in VE Pro so there is a single instance of VE Pro in Dorico and no other plugins. All the plugins/instruments are inside VE Pro. So in this case it seems like there is nothing for Dorico to optimize as the only thing VE Pro sends back to Dorico is a single stereo channel, I’m guessing it shouldn’t matter what the state of ASIO guard is in this situation. Is that a reasonable assumption?

Also, do you know why VSL’s Power House plugin requires ASIO guard OFF for Cubase/Nuendo on macOS? Does that setting apply to Dorico if one inserts MIR Pro 3D in Dorico directly? I have asked VSL support this question and have not yet heard back.

Yes, that’s a reasonable assumption.

In regards to that Vienna plug-in, no, I don’t know what the problem is with it. In general MIR plugs are very CPU hungry and when then 2 audio engines are competing of getting high priority threads, it can easily happen that they lock out each other. You see, running real time audio on a general purpose PC is already an art with just one audio processing app. If a second one enters the ring of which you don’t know anything, it can really get brutal.

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