Memory & Performance Profiler Expert

Overview

Unity profiling expertise for identifying performance bottlenecks, memory leaks, and GC allocation issues. Essential for optimization.

When to Use

•Use when experiencing frame drops
•Use when memory grows over time
•Use for pre-release optimization
•Use when GC spikes occur
•Use for platform-specific profiling

Profiling Tools

code

┌─────────────────────────────────────────────────────────────┐
│                   UNITY PROFILER MODULES                    │
├─────────────────────────────────────────────────────────────┤
│                                                             │
│  CPU PROFILER           MEMORY PROFILER                     │
│  ┌──────────────┐      ┌──────────────┐                    │
│  │ Timeline     │      │ Snapshots    │                    │
│  │ Hierarchy    │      │ Diff Compare │                    │
│  │ Raw Samples  │      │ Object Types │                    │
│  └──────────────┘      └──────────────┘                    │
│                                                             │
│  GPU PROFILER           GC ALLOC                           │
│  ┌──────────────┐      ┌──────────────┐                    │
│  │ Draw Calls   │      │ Per Frame    │                    │
│  │ Batches      │      │ Call Stacks  │                    │
│  │ Fill Rate    │      │ Type Names   │                    │
│  └──────────────┘      └──────────────┘                    │
│                                                             │
└─────────────────────────────────────────────────────────────┘

Common Bottlenecks

Issue	Symptoms	Solution
GC Spikes	Stutters at intervals	Object pooling, cache
Memory Leak	Memory grows	Release, weak refs
Main Thread	Low FPS	Jobs, async
Draw Calls	GPU bound	Batching, atlasing

Key Metrics

Metric	Target (Mobile)	Target (Desktop)
Frame Time	<16ms (60fps)	<8ms (120fps)
GC Alloc/Frame	0KB	0KB
Draw Calls	<100	<500
Triangles	<100K	<1M

Best Practices

•✅ Profile on target device
•✅ Use Development + Profiler builds
•✅ Take memory snapshots before/after
•✅ Check GC allocations every frame
•✅ Use Deep Profile for call stacks
•❌ NEVER profile in Editor only
•❌ NEVER ignore 0.1KB allocations
•❌ NEVER skip mobile profiling

Few-Shot Examples

Example 1: Allocation Tracker

User: "Find memory allocations."

Agent:

csharp

#if DEVELOPMENT_BUILD || UNITY_EDITOR
public class AllocationTracker : MonoBehaviour
{
    private long _lastTotalMemory;
    private int _allocsPerSecond;
    private float _timer;
    
    private void Update()
    {
        _timer += Time.deltaTime;
        
        long current = GC.GetTotalMemory(false);
        if (current > _lastTotalMemory)
        {
            _allocsPerSecond++;
        }
        _lastTotalMemory = current;
        
        if (_timer >= 1f)
        {
            if (_allocsPerSecond > 10)
            {
                Debug.LogWarning($"High allocations: {_allocsPerSecond}/sec");
            }
            _allocsPerSecond = 0;
            _timer = 0;
        }
    }
}
#endif

Example 2: Frame Time Monitor

User: "Display performance stats."

Agent:

csharp

public class PerformanceHUD : MonoBehaviour
{
    private float _deltaTime;
    
    private void Update()
    {
        _deltaTime += (Time.unscaledDeltaTime - _deltaTime) * 0.1f;
    }
    
    private void OnGUI()
    {
        float fps = 1.0f / _deltaTime;
        float ms = _deltaTime * 1000f;
        
        string text = $"{fps:0.} FPS ({ms:0.0}ms)";
        
        var style = new GUIStyle();
        style.fontSize = 24;
        style.normal.textColor = fps < 30 ? Color.red : 
                                  fps < 60 ? Color.yellow : Color.green;
        
        GUI.Label(new Rect(10, 10, 200, 30), text, style);
    }
}

Example 3: Memory Snapshot Comparison

User: "Check for memory leaks."

Agent:

code

Workflow:
1. Play game to main menu
2. Memory Profiler → Take Snapshot (Baseline)
3. Play through game loop
4. Return to main menu
5. Force GC: System.GC.Collect()
6. Take Snapshot (After)
7. Compare → Look for:
   - New objects not released
   - Growing collections
   - Texture/mesh duplicates

Profiling Checklist

• Profile on target hardware
• Check CPU Timeline for spikes
• Verify 0 GC alloc in Update
• Monitor memory over 5 minutes
• Check draw calls and batches
• Test worst-case scenarios

Related Skills

•@object-pooling-system - Fix GC allocations
•@mobile-optimization - Platform limits
•@lod-occlusion-culling - Rendering optimization