I know that the general performance of N15 has been discussed already but I could’t find any topic releated to this weird behavior. Please correct me if I’m wrong.
The setup: I create an empty project, Control room is enabled but no plugins whatsoever. Asio meter looks like this (totally fine):
Then I start adding stuff (I tested random Plugins, VST instruments, tried using only steinberg stuff or only third party plugins, makes no difference) and after a while the asio meter jumps quite high suddenly. Then I delety every track and every vst insert, so that I end up with an empty project again but the asio guard utilization keeps beeing much too high:
When I go into the audio setting and force a audio engine reset (for example by switching the asio guard level from normal to high, clicking apply and then back to normal, apply), the asio guard utilization gets back to normal.
I tried it on two different machines (both Win 11), one desktop with an AMD processor, one Laptop with an Intel processor, different interfaces (RME, UAD, even tried Asio4all), tried different buffersizes e.g. but the issue always comes up after a while. I never had and still don’t have this issue with N14 (I need to keep working in N14 because of that).
Does anyone else have this issue? Anyone a solution or a workaround (exept resetting the audio engine all the time)?
Update: It seems to need some kind of trigger, for example a higher asio guard load while playing an VST instrument. If I just load an empty session and do nothing, then this behavior does not occur.
Also clickig “reset device” in the audiosystem settings (I hope I translated the german terms correctly) doesn’t get rid of the high asio guard load. Also deactivating asio guard and re-activating it again doesn’t get rid of the “ghost load” in the asio guard. Only changing the asio guard level (ASIO-Guard Pegel in german) to another setting, clicking apply and then go back to the original setting and click apply resets the asio guard load.
Onyone any idea why?
Ok, the meter shows an unusually high asio guard load, but have you checked if this is relevant?
I mean in the sense of does this translate to a lower net performance ceiling, or is this just some sort of metering artifact or something? After it is in this state what happens if you keep increasing the load? Does is increase from that point or does it take a lot of plugins beford the meter starts rising again?
Not that it shouldn’t be fixed, but perhaps its innocuous.
yes it is performance relevant unfortunately… Some heavy load sessions start to become unplayable when this error occurs and after resetting the asio guard level, I’m having a playable session again. It does not show in terms of cpu load though, the actual cpu load stays the same but something strange happens inside Nuendo somehow 
ufff that’s a bummer!
hope you can find a solution soon!
Thanks, I hope so too!
I did another test, bumped up the asio guard load to around 70%, then after a while it went up to 95-100% and after resetting it, it went down to 70% again. So it’s a lot of performance that gets lost unfortunately.
I also checked if enabling/disabling Control Room makes any difference (it doesn’t).
Well, here’s a quick update on this issue—maybe someone else is having the same problem and has a solution:
I uninstalled Nuendo and did a completely clean reinstall (after deleting all preset folders, including those from previous versions). That fixed the problem (that was with version 15.0.20).
Now I’ve updated to version 15.0.30 and the problem is back 
Does anyone have any idea what’s going wrong here?
