So your ASIO guard is at max, and your project does not wan't to play your project anymore. Your buffersize is maxed out and you wan't to add more plugins.

Add an external effect on any track on your project and all of a sudden your ASIO guard is not maxed out anymore and you can add more plugins.

I don't understand myself why this happens, maybe somebody with more knowledge on Cubase can, but I just noticed this is reality.
I was mixing a song with some outboard in one of my channels and the project was running fine. After removing the external effect from the insert of the channel the ASIO was maxed and the project would not play anymore.

Can somebody explain to me why this happens?
Well in any case, maybe some of you can try this out and let me know if you get more headroom in your ASIO guard meter like this.

I'm running Cubase 12 with Orion 32 HD on my PC with Ryzen 9 5900X.
It sure feel kind of stupid that I'm maxing out my ASIO guard when my CPU is only at 45% (edit:21%), but I guess I might just be running out of threads, since Cubase really depend on them, not the CPU power.

Have fun!

I can actually confirm that - there is a noticeable decrease on the ASIOGuard load in the C12 performance meter when having one external effect inserted somewhere in the project.
I can't really explain why. It might be some extra buffer that is used when inserting an external effect. Might be just measured differently
The overall CPU usage is not really relevant as a measurement. In earlier Cubase versions the performance meter was directly correlated on the most used CPU core in the system, so if you had one saturated core and 7 other idling, the meter was at 100%.
It is not like that anymore, though, as Cubase scheduling was adapted to more and more cores, and has become somewhat better at spreading the load over many cores. This comes at a price of more overhead for thread synchronization, as far as I can see.
I simply don't know how the performance meter measurement works, Steinberg don't tell it, so it is just guesswork.

I rarely have problems with the ASIOGuard load anyway, less so with my new Ryzen 7950, but the realtime path (peak) can still be a problem, especially with some headphone correction plugins loaded in the control room and e.g. a CPU intensive VSTi in record/monitor mode.

yeah, so for me, inserting an external effect drops the ASIO guard level from max to 80%, which is a big difference.

Thanks so much @ Nevelous for posting this. It really works and my maxed-out projects run again without dropouts. What a great find!

I added a unused dummy track with an unused external effect on my templates.

atleast it's safe to use this, if you are working in the box, and when exporting/bouncing a track, you just remove/disable the dummy track.

Only thing I'm scared of is that when I export an audio mixdown live with outboard, the sound could start distorting because the buffer / ASIO running on "fake" fumes. I don't know was I hearing it or was it just my imagination, but I suspect it kind of distorted at one point in the bounce. Cannot be sure, because the material I was mixing was so saturated :D

I'm still trying to figure out what is going on here under the hood and I'm hoping somebody with knowledge could tell me what is going on and are there dangers in this in live export situations (like I thought I was hearing).

Good point as for exporting I'd have to disable the effect.