Display Performance

Systematic diagnosis for frame rate issues on variable refresh rate displays like ProMotion.

When to Use

Use this skill when:

Your app runs at 60fps on a ProMotion (120Hz) device
MTKView or CADisplayLink isn't reaching expected frame rate
You're experiencing micro-stuttering despite good average FPS
You need to configure CAMetalDisplayLink for precise timing
You want to monitor animation hitches in production

Example Prompts

"My Metal app is stuck at 60fps on iPhone Pro. Why?"
"How do I configure MTKView for 120Hz?"
"Why does UIScreen say 120 but I'm getting 60fps?"
"What's the CADisableMinimumFrameDurationOnPhone key for?"
"How do I use present(afterMinimumDuration:) for smooth frame pacing?"
"How do I detect frame drops in my Metal app?"

What This Skill Provides

Decision tree for diagnosing why you're stuck at 60fps
Render loop configuration patterns (MTKView, CADisplayLink, CAMetalDisplayLink)
System cap detection (Low Power Mode, thermal throttling, Adaptive Power)
Frame pacing APIs to eliminate micro-stuttering
Hitch mechanics (commit hitches vs render hitches)
Production telemetry with MetricKit

energy — Use when frame rate issues are battery-related or you need power-aware rendering
performance-profiling — Use for general Instruments profiling before diving into display-specific issues
swiftui-performance — Use for SwiftUI view update performance, not Metal/CADisplayLink rendering