Bottleneck Analysis

Before attempting to optimize quality settings, you must know which hardware stage is limiting your framerate.

Optimizing shadow resolution or texture sizes will produce zero framerate gain if your game is CPU-bound on complex pathfinding or physics. Conversely, stripping mesh colliders will not help a scene choked by fill-rate and post-processing.

                  ┌──────────────────────────────┐
                  │ Is GC Alloc > 0 KB / Frame?  │
                  └──────────────┬───────────────┘
                                 │
                 YES ────────────┴──────────── NO
                  │                            │
                  ▼                            ▼
       [MEMORY_GC_PRESSURE]       ┌─────────────────────────┐
                                  │ Compare CPU vs GPU Time │
                                  └────────────┬────────────┘
                                               │
                       ┌───────────────────────┴───────────────────────┐
                       ▼                                               ▼
          GPU Time > CPU Time + 1.0ms                    CPU Time > GPU Time + 1.0ms
                       │                                               │
                       ▼                                               ▼
           [GPU_SHADOWS_AND_RASTER]                      Compare Main Thread vs Render
                                                                       │
                                                       ┌───────────────┴───────────────┐
                                                       ▼                               ▼
                                              Main Thread High                Render Thread High
                                                       │                               │
                                                       ▼                               ▼
                                              [CPU_MAIN_THREAD]               [CPU_RENDER_THREAD]

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Bottleneck Classifications

BottleneckAnalyzerService.cs analyzes the median baseline data and outputs a verdict with confidence ratings:

1. GPU_SHADOWS_AND_RASTER

• Condition: Measured GPU frame time consistently exceeds CPU main thread time by $> 1.0\text{ ms}$.
• Candidate Solutions: Reduce shadow distance, lower shadow cascade counts, decrease render scale, disable SSAO or depth-of-field.

2. CPU_MAIN_THREAD

• Condition: CPU main thread time exceeds GPU time, with low render thread wait.
• Candidate Solutions: Adjust LOD bias to decrease mesh complexity, reduce particle simulation counts, optimize scripts.

3. CPU_RENDER_THREAD

• Condition: Render thread time dominates, indicating high draw call submission overhead.
• Candidate Solutions: Increase GPU instancing, enable SRP Batcher, adjust LOD distances to reduce batch counts.

4. MEMORY_GC_PRESSURE

• Condition: Profiler records non-zero GC allocations on hot frames, triggering periodic GC hitches.
• Candidate Solutions: Audit zero-allocation buffers, convert classes to structs, eliminate string concatenations in update loops.

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Confidence Limits

The analyzer reports an explicit confidence percentage based on the separation of timings across all valid frames. If CPU and GPU timings are within $0.5\text{ ms}$ of each other, DeviceFit reports: Bottleneck: BALANCED / CO-LIMITED (Confidence: LOW). This warns you that improving one subsystem will immediately hit the other bottleneck ceiling.