Fable Broke My App and Couldn't Fix It

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The creator discusses performance issues in the T3 Code app, specifically concerning CPU and GPU usage, and how they attempted to debug and resolve the problem using Fable and other tools. The conclusion is that the issue is complex and not easily solved with current tooling, leading to a PR being opened to address it.

The T3 Code app suffers from significant performance bottlenecks caused by inefficient CSS animations, particularly 'animate-pulse', leading to high GPU usage. While a fix was identified and implemented, the debugging process highlighted the complexity of such issues.

• T3 Code App Performance

  The T3 Code app has severe performance issues causing high CPU and GPU usage, particularly with CSS animations and on 120Hz monitors.

  • 2:20 High GPU usage observed, especially on 120Hz monitors.
  • 25:50 Specific CSS animations, like 'animate-pulse', are identified as major culprits due to high rendering cost.
  • 17:20 Browser task manager shows high GPU process utilization, sometimes exceeding 20%.
• Debugging Process

  Debugging performance issues requires a systematic approach, starting with broad analysis and narrowing down to specific problematic components.

  • 3:50 Initial investigation involved checking Chrome, electron, and browser fixes globally.
  • 17:20 The creator traced the issue to specific files and animations using browser dev tools and task manager.
  • 23:30 A PR was opened to address the identified animation issues after other potential causes were ruled out.

• 2:20 The T3 Code app exhibits severe performance issues, leading to high CPU and GPU utilization, especially on 120Hz monitors and with certain CSS animations.
• 3:50 The creator initially suspects problems with Chrome and browser fixes, but later identifies specific CSS animations, particularly 'animate-pulse' and the terminal icon, as the main culprits.
• 17:20 Debugging with browser task manager revealed high GPU process usage, peaking at over 20% for the GPU process itself.
• 17:50 A proposed fix involves making the animation static when the terminal is inactive and using a finite pulse when active, reducing GPU usage.
• 17:50 The creator experimented with disabling different animations and found that removing 'animate-pulse' drastically reduced GPU usage.
• 19:20 The issue was traced to specific elements originating from 'Sidebar.tsx' and 'ThreadStatusIndicators.tsx', involving four synchronized pulse animations.
• 25:50 The 'animate-pulse' animation was identified as the most expensive offender, causing high GPU load due to its constant re-composition of elements.