Cubase 15 GUI stuttering when using massive MIDI tracks

I work with MIDI recordings of solo piano pieces with very large numbers of key strokes (similar to Liszt etudes) and of course sustain pedal data. I recorded about 20 sessions (takes), each about one hour long, and stored those in the lanes of one MIDI track. There is nothing of relevance (plugins, FX, other tracks) other than the one MIDI track.

I then noticed that the Cubase GUI started seriously choking, even when nothing was playing. E.g., just trying to move the divider between main zone and lower zone made the GUI freeze for 2–3 seconds before the zone was resized. Same if I try to zoom horizontally.

I have a powerful MacBook Pro Max (M1, 2021?) and Cubase Pro 15.0.6. I am not sure if this would have happened in older Cubase versions, since this is my first project with such massive amounts of MIDI data.

I hacked/masked the problem by sticking the MIDI track into a folder track and closing the folder track, so that Cubase doesn’t attempt to draw a detailed image of all MIDI events in the main zone.

MESSAGE TO STEINBERG:
I think Cubase should detect when it has too much MIDI data to draw in the main zone, and then either reduce the level of detail, or give the drawing action lower priority. It should not cause the GUI to choke, which makes editing work unfeasible.

Hi,

Are you on macOS 15 or 26, please?

MacOS Tahoe 26.1.

Hi,

There is a performance bug in macOS 26. Cubase 15.0.5 was affected heavily. Cubase 15.0.6 tried a workaround that works for some users (unfortunately, it seems not for all). Maybe you are affected too. Please try searching for more info; it has already been discussed here on the forum.

Apple is informed about the issue.

Hey @Matthias_Heymann ,
Would you mind sharing one of these projects with us? It would be a great help. Thanks!

Is there a way to send it to you without publishing it on this forum for everyone to see?

Hi,

Yes, you can send it via Private Message.