Cubase 15.0.21 GUI redraw errors / realtime audio instability on Apple Silicon

Cubase
, ,
1

My System’s Details :

  • Mac mini M4 Pro (48 GB RAM / 1 TB SSD)

  • macOS 26.4.1

  • Cubase 15.0.21 (Native and Rosetta Both)

  • Audient iD4

Issue Summary :
I experienced significant realtime audio processing instability in Cubase 15 on an Apple Silicon Mac mini M4 Pro despite the system having substantial CPU/GPU resources available.

The instability was especially noticeable during common editing and playback operations involving:

  • faded audio events

  • time-stretched/transposed audio (Musical Mode and Manual Stretch)

  • enabling/disabling cycle range

  • looping playback

  • rapid timeline navigation

  • waveform redraw during playback

Observed audio issues before workaround:

  • random clicks/pops during playback

  • short audio interruptions

  • inconsistent realtime responsiveness

  • spikes during playback of faded or transposed audio

  • temporary playback instability when toggling cycle mode

  • occasional lag when looping sections repeatedly

Workaround discovered:
Disabling GPU Acceleration in Cubase significantly improved realtime audio stability.

Additionally, increasing the Disk Preload Buffer from 2 seconds to 4 seconds further improved playback consistency and reduced audio interruptions.

After these changes:

  • realtime audio became substantially more stable

  • playback of faded/transposed audio improved

  • cycle playback became more reliable

  • fewer interruptions occurred during editing/navigation

However, disabling GPU Acceleration introduced GUI rendering problems.

Observed GUI issues with GPU Acceleration OFF:

  • GUI regions fail to redraw correctly

  • portions of the interface remain visually blank until hovered

  • waveform rendering becomes sluggish/choppy

  • fullscreen toggling forces GUI refresh

  • mixer/editor redraw responsiveness decreases

  • scrolling waveform display becomes less smooth

  • moving the mouse over affected regions repaints them correctly

Additional observations:

  • issue appears cosmetic only

  • no audible degradation after workaround

  • exports render correctly

  • audio engine stability improves despite GUI regressions

Behaviour appears related to:

  • GUI redraw/compositor invalidation

  • Apple Silicon/macOS graphics scheduling

  • Retina/high refresh display rendering interaction

Additional Settings :

  • fixed 60Hz refresh rate

  • HDR disabled

  • Stage Manager disabled

  • “Displays have separate Spaces” disabled

  • Default display scaling instead of “More Space”

GPU Acceleration ON:

  • smoother GUI behavior

  • better waveform rendering

  • fewer redraw glitches
    BUT:

  • worse realtime audio stability

  • more frequent audio interruptions during fades/transposed playback/editing operations

Request:
Please investigate the interaction between Cubase 15’s GPU acceleration/rendering pipeline and realtime audio processing on Apple Silicon Macs.

The current behavior forces a tradeoff between:

  1. stable realtime audio processing
    and

  2. stable GUI rendering

on a high-performance Apple Silicon system where both should ideally function correctly simultaneously.