Cubase 12 Upgrade ASIO-Guard Issue

@pkmusic Exactely the same behaviour I have over here.

It’s absolutely possible that a specific plugin or a combination are the culprit(s). But I have no idea where to start looking. Superior Drummer 3 could be it, but I don’t have another drumsampler anymore to try and check my routing with the multiple outputs in 6 groups going in two busses. I believe it could have something to do with multi outputs and a complicated routing together with a specific plugin, but e.g. removing all UAD plugins in those cahnnels and groups didn’t help.

I’m lost with this problem right now.

1 Like

I too can confirm Asio Guard spikes here in Cubase 12. Never had this problem in Cubase 11.

It feels like Asio Guard might be overworking itself in order to lighten the load on “realtime” and “peak”? Not sure how it works, but it does kind of feel that way.

I’m noticed the same problem while using the avenger synth

It must be a nightmare to attempt to test software and factor in another 50% worth of foreign add-ons. Perhaps in the changes away from VST2 there is a memory allocation issue. It runs so well with the demo songs. Possibly on Macs this is issue is not as bad? Need a poll there . . .

Hi Matthias,

I’ve checked a couple of projects on Cubase 12, none of the effects plugins used in them had any of their own multi-processing. Yet, the Asio Guard spikes still occur.

As far as VST instruments go, like Kontakt, I’ve tried both on and off for multi-processing. No difference. Asio Guard spikes still occur.

Using Windows 10. Thanks.


Hi all.

Just a quick update.

Apple released a point update to Big Sur this morning. It’s now at 11.6.5. I performed the update. The random CPU spikes and related issues are not happening for me anymore. I’ve tried creating simple projects using VSTs like Padshop, Omnisphere, and Kontakt and I have not hit a random spike yet. Projects that were formerly spiking are not. (I do not use VST based multiprocessing if I can avoid it btw.)

I have no idea whether or not the OS update is related to the lack of issues, but I wanted to flag it for the group. Perhaps someone else can give it a try?

I have run across a different problem with Aggregate devices. It is not germane to this topic so I will post about that separately in the forum.

Cheers all.


What is that? Thanks.

Maybe I’m being thick, but what do you mean by a plugin with ‘Multiprocessing’? Can you give some examples?

Hi @SledDriver ,
Multiprocessing means processing on multiple cores in the same time. When running the plugin or VSTi inside a host application - like, e.g. Cubase - the host is taking care for the multi-core audio processing . If a plugin is doing its own multicore processing, it is likely to compete with the sequencer’s processing threads which can lead to bad performance. That’s why Steinberg recommends to let Cubase take care for handling the processing and let the plugins’ multicore processing disabled - in case they offer to disable it (e.g. Kontakt or Halion have that option).

Aha. Thanks for that. Is there an easy way to see which of your plugs have this? It isn’t indicated in the Plugin Manager. I wonder if there is a list anywhere?

1 Like

Having the same. Windows 10 (all current updates), Ryzen 3950X, Cubase 12.

My orchestral template worked fine in Cubase 11, but loading it in Cubase 12 causes huge CPU spikes making it unusable. Have gone back to Cubase 11. Disappointing for an ‘upgrade’ that promised to be faster/sleeker/optimised.

I’ve got Hyperhtreading on, but given it works perfectly at 128sample buffers on Cubase 11, I’m not sure that is the issue.

1 Like

An Aggregate Device is a virtual device driver for Mac OS…with an Aggregate Devices it is possible to combine different physical inputs and outputs from different interfaces and treat them like one virtual device. The OS ensures the devices are synced and locked to each other. The DAW just sees and treats it like a single device.

It seems like there is a limit to the number of I/O supported in aggregate devices. The full question is here:

Thanks for asking.


I’m on this thread as I’m finding very uneven core loading/allocation on my 5950x.
I’m a big acoustica aqua user an all their plug-ins are multithreaded with no way of turning off.

It will be interesting to see how this gets resolved.


1 Like

I have this issue too (and have raised a ticket to that effect). New project in CB12, 256 samples latency, single audio channel with either Amplitube 5 or Line 6 Helix Native and audio glitches continuously. I’ve reverted to CB11 for now as CB12 is unusable. Same thing works fine in CB11. Win 10, i9 processor, 32Gb RAM, SSL 2+ interface.


Wow! Using my Apollo Twin for my portable setup I’m always short of inputs. I can plug the Focusrite Octapre into the ADAT input but sometimes I only need two more inputs. Are you saying I could use my Focusrite Scarlett and the Apollo at the same time?

If you are on a Mac, yes.

Instructions here:

You CAN do this…please keep in mind that creating an Aggregate device comes at the expense of latency…so your overall input to output latency will increase to a degree.

So …no free lunch…but it does work.

Thanks so much! I found the “create aggregate device” in Audio/Midi Settings. So cool! Never knew that option was available. I can deal with increased latency when recording just audio. Then switch devices to just the Apollo for overdubbing and mixing. Can’t wait to try this.

1 Like

In case the plugin offers to configure its multiprocessing, you will usually find the setting in the plugin setup/ options/ preferences dialog (e.g. HALion: Options tab, Kontakt: Settings).

1 Like

as this seems to affect only specific systems, we would like to know more about your OS, CPUs and VSTi/ Plugins which are showing this behavior.
Could you please all reply to my post here and list:

  • System information:
    – your OS platform (Apple Intel, Apple Silicon, Windows)
    – your OS version number (like Win 10.1809, macOS 11.6.4,…)
    – your CPU model and number of cores
    – does C12 always fail ? Or just from time to time?
  • Project Details:
    – Sample Rate
    – Asio Guard Level: Low, Normal, High?
    – Audio Buffer size
    – number of VSTi/ Audio/ Midi tracks
    – VSTis in the affected project
    Thanks very much for your support!
    Test Engineer at Steinberg