Performance Profiling
DevOpsDiagnose and resolve performance issues: stat commands, Unreal Insights, GPU/CPU bottleneck identification, and memory profiling.
/skill performance-profiling What This Skill Does
Performance Profiling helps you diagnose and resolve performance issues in UE5 projects using a systematic, profile-first approach. This skill teaches you to identify whether your bottleneck is GPU, game thread, or render thread using stat commands, then drill into the specific cause with detailed GPU pass timing, CPU profiling, or memory analysis. You will learn to use Unreal Insights for deep frame-by-frame trace analysis, understand frame budgets for 30, 60, and 90 FPS targets, and apply targeted optimization strategies across rendering, gameplay logic, draw calls, and memory to hit your performance goals.
Covers
- Stat commands for real-time performance monitoring (stat unit, stat GPU, stat fps)
- Unreal Insights: detailed CPU/GPU profiling and trace analysis
- GPU profiling: render pass breakdown, shader complexity, and overdraw visualization
- CPU profiling: game thread, render thread, Blueprint cost, physics, and AI timing
- Memory profiling: texture memory, mesh memory, VRAM, and asset auditing
- Common optimization strategies organized by subsystem
- Frame budget breakdown for 60fps, 30fps, and VR 90fps targets
- Hitch and stutter diagnosis: shader compilation, asset loading, and garbage collection
Does Not Cover
- Nanite-specific optimization tuning → Nanite Optimization
- Lumen lighting performance tuning → Lighting Fundamentals
- Network performance and replication optimization → Multiplayer Basics
- Platform-specific profiling tools (PIX, Razor, PerfDog) → Platform-specific skills
How to Use
Invoke this skill in Claude Code:
/skill performance-profilingThis skill is also auto-detected when your prompt mentions performance, FPS, frame rate, profiling, optimization, bottleneck, GPU, CPU, stat, or slow intent. AgentUX will automatically activate Performance Profiling when it recognizes relevant context in your request.
Key Unreal Engine Concepts
| Concept | Description |
|---|---|
stat unit | The primary profiling command showing per-frame timing for Game, Draw, GPU, and RHI threads: the largest value is your bottleneck. |
stat GPU | Breaks down GPU time by render pass (BasePass, Shadows, Lumen, PostProcessing) to identify rendering bottlenecks. |
Unreal Insights | A deep profiling tool for frame-by-frame trace analysis with timing views, counters, and memory tracking. |
Shader Complexity View | A viewport visualization mode that color-codes surfaces by material cost: red indicates expensive shaders. |
Frame Budget | The maximum milliseconds per frame for a target FPS: 16.6ms for 60fps, 33.3ms for 30fps, 11.1ms for VR 90fps. |
Size Map | A developer tool that visualizes disk and memory usage per asset type and directory for identifying oversized content. |
Related Skills
nanite-optimization
Nanite geometry optimization for reducing draw calls and GPU cost
lighting-fundamentals
Lumen and shadow performance tuning for GPU-bound scenes
niagara-basics
Particle system optimization for translucency and overdraw reduction
blueprint-basics
Blueprint optimization for reducing Tick overhead and CPU cost
What You'll Learn
- How to quickly identify whether your bottleneck is GPU, game thread, or render thread
- How to use stat GPU to find the most expensive render pass in your scene
- How to capture and analyze traces in Unreal Insights for detailed profiling
- How to diagnose hitches and stutters caused by shader compilation, loading, and garbage collection
- How to audit memory usage and identify oversized textures and asset reference chains
- How to apply a systematic optimization strategy ordered by impact