Cubase 12 Upgrade ASIO-Guard Issue

Same here on Mac with 10.15.7.
Mendel mixed like this

Austin Hull mixed more load

But no drop outs or any other problems

But the strange thing is that deleting my FX sends makes almost no distance. All my heavy duty plug-ins are UAD. Except for a few Waves. On my system it’s the number of tracks. Not groups. It’s as if playing back audio is the issue. The Austin Hull track has very little audio files.

I also experiencing Asio inconsistences. When I reload project it normalize asio meter, but turning some plugins on-off on master bus it’s getting worse.

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Do you work with UAD audio card? You should change latency up and down to resync. You lost sync… I think this is UAD driver issue on windows. I had the same trouble but last 2-3 months not happend anymore. How strong CPU are you using?
Since I have new PC is everything much better.

No, I’m not using an UAD audio card, I’ve got a RME Audio FirefaceUCX2.

My Computer is Intel Core i7-3930k running 6 cores at 3.2Ghz and having 32 GB of memory. So it’s old and weak, but works for my needs just fine with Cubase 11.

No problem, I had also 6 core Cpu till december and it was not bad at all. Try to change latency next time you get that buzzing.

Sure that’s how it should work but with Cubase12 increasing the ASIO buffer size makes no difference for me. The buzzing is still there.

This buzzing sound, it sounds like you are out of sync and not out of CPU performance. You should check your card settings. Did you connect some other digital audio device in last time?
Did you switch to high power sheme or steinberg power sheme in cubase?
Check also in windows device manager if your usb drivers are OK, no yellow triangles or somethig like that.


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Having issues here as well. (WINDOWS I7-8700K)
Asio guard on “LOW”, works much better than on “HIGH” here, which does not make any sense to me at all. On “HIGH” I cannot even play the project, on “LOW” I get some random drop outs here and there.
This was definitely not the case on C11. Lets open a support case everyone please. This way this will be prioritized.

Hi all,

We are looking into the issue and are working on fix. It seems to be related to plug-ins that have their own multi-processing management. We are on it.

What is your experience when you turn off “Multi-Processing” in the plug-in itself?

All the best,


Hi Matthias,
thanks for the update and good luck!
In my case just 1 VST3 instance of Amplitube 5 leads to the peaks on the performance meter. Hope that helps.


Hi Matthias, thank you for joining the discussion! Very much appreciate your input here, and confirmation of the issue we are all experiencing.

Here is my experience and why I created the post. On my first play with C12, I noticed some usual behavior when running the demo track “Cubase 12 - Pop Demo By Austin Hull.cpr_MIXED”. Simply arming, then unarming the record button of an instrument track resulted in an audible dropout/click when the ASIO-Guard is set to Low or Normal. For me, increasing AG to High improved the performance and I could no longer hear the dropout clicks. At this this point I was not even looking at the performance meters, just listening to the track. I discovered this by browsing through the demo project selecting different tracks (audio tracks, instruments tracks, folders). For me with my setup, this is a new issue I did not experience in C11.

To test further, I then ran the same demo session in C11 and noticed I did not have the same issue with the ASIO-Guard settings and could run the project with AG set to Low with no dropout/clicks. ( I understand the demo project was created specifically for C12, so this is not a completely fair comparison as several plugins are not available in C11). But this did confirm, at least for me, that there is some difference in process handling in C12 and C11.

As others have joined in the discussion and shared their experiences, I feel it has been confirmation that there are some issues with C12. My hope is that this discussion and shared experiences has helped toward pinpointing a possibly cause and will lead toward a fix.

I personally value your feedback and input here and thank you again for joining in the discussion. I am sure others will be happy to share their experiences in more detail if you should have any further questions, or specific testing you would like us to perform.

Kind regards,

I’d like to just give a shout out to Daniel for starting then curating this discussion so artfully, and to everyone who added really helpful observations and suggestions. This thread did not degenerate into a “C12 sucks!” miasma of unhelpful posturing.

FWIW, although my challenges with C12 share some similarities with Daniel, there is an added dimension: I get random, continual CPU spikes that peg the CPU meter even with very few (sometimes only 1 or 2) plugins instantiated. I noticed this first with Kontakt, but it seems to affect almost everything. ONE time I had no CPU spikes even after leaving a small project looping playback overnight. I also successfully played that same project later with all tracks record enabled. I thought I was in the clear, but the very next project I started, the random CPU spikes returned. (Unfortunately all that I remember about the problem free project is that I was using ONLY VST3 versions of plugins, but I don’t remember the specific plugins I used.)

Changing various buffer and ASIO guard settings have had little real effect during all of this.

Thank you!

iMacPro 10core, 64gb ram, Big Sur 11.6.4, Radeon Pro Vega 56 8 GB


Thanks Matthias, we all appreciate yours and Steinberg’s help and hard work.

However, I have one glaring question: How come none of the beta testers noticed this? It seems like a huge issue that is extremely noticeable at first. Not to keep repeating myself but I had the same question when Cubase 10.5 was released and it had the same type of extreme CPU spikes. How would something like that NOT have gotten noticed or addressed before release?


I have only two plugins with a Multi-Processing option in most of my projects:

  1. Superior Drummer 3
    That is already running with no. of cores set to 1 over here, since Toontracks MP is known to be broken when running inside a Host running on MP as well.

  2. U-He Repro and Diva
    Both of them have their best performance with MP “on”. I know that Urs thinks otherwise and recommends turning it off. But Urs is on Mac, he rarely has experience with PC anymore these days. While turning MP off might be useful on a Mac, it really works VERY well in Cubase on Windows.

Having said that, the plug-in that causes the problem over here is Superior Drummer 3. Activating a MIDI-(not instrument) track going to SD3 as a rack instrument makes the CPU Meter going mad and causes a lot of crackling and noises due to CPU overload.

That does not happen with C11. When I load the very same song in C11, activating that said MIDI-track no such thing as in C12 happens. No crazy CPU Meter spiking, no crackles, no noise. It just works.

What is also strange is the significant delay with muting of audio when switching back from that problematic track to any other track. The CPU Meter goes to Zero and then back. It seems like Cubase is unloading plugins and loading them again.
Again that does NOT happen with C11 in the exact same project.

Another thing, though I don’t know if that is of any use for you:
SD3 is one of the few VST2-plugins I still use. In current projects I also have a couple of VSTs (mainly Soundtoys and UAD), but SD3 is the only VST2 VSTi that I use.

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Thank you George for the kind words! I too, am very pleased and encouraged by everyone’s productive participation. I appreciate you all for sharing your insightful contributions! If this discussion helps improve Cubase, even if just a little, we all benefit in the end!

I think we all share the same goal/wish here - we just want Cubase to work the best it can!

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Regarding the Midi to Instruments track - That’s a very interesting addition to the discussion. Thank you Rainer_Hain for sharing the details.

Let’s see what Matthias reports back to us regarding “multi-processing” currently under investigation.

Video evidence of the issues I’m having. I have no idea how to get past this. It’s rather disappointing. I accept it could be down to even a specific plugin but where do you start with that?
C12 vs C11 performance issues.

Yep I must confirm I’ve had the same issue here - very obvious issues with ASIO Guard and in fact out-of-character CPU spikes in general with VSTis engaged in CB12 … have reverted with current projects to using 11 for now until a fix is released.

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