Performance Budgets & Profiling (Blueprint Production)

What/Why: Establish concrete performance targets and profiling workflows to maintain 60fps+ on target platforms with Blueprint-heavy projects.

Prereqs

• Unreal Insights installed and configured
• Target platform dev kits for accurate profiling

Performance Budgets (Concrete Targets)

Memory Budgets

• Mobile (iOS/Android): Total 2GB, Game 1.2GB, Blueprints 200MB, Audio 300MB
• Console (PS5/XSX): Total 8GB, Game 6GB, Blueprints 800MB, Audio 1GB
• PC High-end: Total 16GB+, Game 12GB, Blueprints 1.5GB, Audio 2GB
• VR (Quest/PICO): Total 1.5GB, Game 900MB, Blueprints 150MB, Audio 200MB

Frame Time Budgets (60fps = 16.67ms total)

• Game Thread: 8-10ms (Blueprint logic, gameplay updates)
• Render Thread: 10-12ms (draw calls, state changes)
• GPU Frame: 14-16ms (geometry, lighting, effects)
• Blueprint VM: 2-3ms maximum (event processing, calculations)

Blueprint-Specific Optimization

Steps

1. Blueprint Profiling Setup

• Enable Blueprint Profiler in Editor Preferences → Performance
• Use Stat BlueprintGraph to see per-Blueprint execution time
• Monitor with Stat Memory for Blueprint memory allocation
• Profile on device: package Development build with Blueprint profiling enabled

2. Blueprint Performance Patterns

• Avoid: Complex math in Tick; use Timers at 10-20Hz instead
• Cache: Expensive lookups (GetPlayerController, GetGameMode) in Begin Play
• Pool: Arrays and objects; clear/reuse vs create/destroy
• Batch: Multiple small operations into single events (inventory updates)

3. Memory Management

• Use Stat Memory Blueprint to track Blueprint object allocation
• Clear large arrays when not needed: Array.Empty() vs Array.Reset()
• Avoid circular references in Blueprint object graphs
• Use Soft References for non-critical assets; Hard References for critical gameplay

4. GPU Performance with Blueprints

• Use Stat GPU and ProfileGPU console command
• Monitor Blueprint-driven material parameter changes (avoid per-frame updates)
• Batch Blueprint FX spawning; use object pools for particles
• Control LOD via Blueprint: Set LOD on Skeletal/Static Mesh Components

5. Insights Integration Workflow

• Launch game with -trace=cpu,gpu,memory,blueprint
• Capture 30-60 seconds of typical gameplay
• Analyze in Insights: find Blueprint hotspots in CPU timeline
• Focus on: Event frequency, large allocations, long-running functions

6. Automated Performance Gates

• Create BP_PerformanceMonitor (GameInstanceSubsystem)
• Functions: CheckFrameRate(), CheckMemoryUsage(), LogPerformanceWarning()
• Trigger warnings when budgets exceeded; disable features dynamically
• Use DataAsset for platform-specific thresholds

Data

• DA_PlatformBudgets: frame time, memory, and quality targets per platform
• Performance telemetry: log framerate percentiles, memory peaks, Blueprint hotspots

Networking

• Network thread budget: 2-3ms for replication processing
• Monitor with Stat Net: packet size, send rate, processing time

Performance

• Critical: maintain budgets under stress (100+ Blueprints active, heavy combat)
• Profile worst-case scenarios: maximum players, complex UI, streaming loads

Testing

• Automated tests: spawn 100+ Blueprint actors, measure frame time consistency
• Platform validation: run on minimum spec hardware for each target
• Stress scenarios: memory pressure, thermal throttling, background apps

Production Monitoring

1. Runtime Performance Telemetry

• Collect frame rate percentiles (1%, 5%, average) per play session
• Track Blueprint execution spikes and memory allocation peaks
• Log when dynamic quality scaling triggers due to performance pressure

2. Blueprint Complexity Metrics

• Nodes per Blueprint (target: <500 for gameplay, <100 for UI)
• Function call depth (target: <10 levels)
• Array sizes and iteration counts in hot paths

3. Platform-Specific Validation

• iOS/Android: thermal throttling response, memory warnings
• Console: loading time validation, suspend/resume handling
• PC: wide hardware range testing, driver compatibility

Suggested prompts

• "UE 5.6 Blueprints only. Create a BP_PerformanceMonitor subsystem that warns when frame time exceeds platform budgets and disables features dynamically."
• "Show Blueprint profiling workflow using Stat commands and Insights to find performance bottlenecks in Blueprint execution."
• "Provide memory budget breakdown for Blueprint-heavy mobile game with concrete MB targets per system."
• "Create automated performance testing Blueprint that spawns stress scenarios and validates frame rate consistency."

Prompts for this example

• "Write Blueprint nodes to measure current frame time and trigger performance warnings when exceeding 16.67ms budget."
• "Show memory profiling setup to track Blueprint object allocation and identify memory leaks in large Blueprint graphs."