WISA Course - Scientific Framework Comparison

This benchmark suite provides an apples-to-apples performance comparison between:

• Flutter (Impeller/Skia rendering engine)
• Native iOS (SwiftUI)

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📜 Documentation

• TECHNICAL.md - Comprehensive technical details about benchmark methodology, implementation, measurement approaches, and results analysis
• Academic Paper - Full scientific documentation in LaTeX

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📊 Metrics Measured

Metric	Description	Implementation
CPU Efficiency	Single-thread performance	Sieve of Eratosthenes (1M primes) on main thread
FPS Stability	Frame rendering consistency	1000-item list with 30s auto-scroll
Memory (RAM)	Memory allocator stress	Complex UI elements with gradients/shadows
Battery Impact	Energy consumption	Battery level delta during GPU test
App Startup Time	Time to Interactive (TTI)	main() → first frame rendered

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🖼️ Screenshots & Video Demo

Below are screenshots and video demos of the apps and their benchmark tests:

iOS App
	demo_ios.mp4
Flutter App
	demo_flutter.mp4

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🏗️ Project Structure

Projects/
├── flutter_benchmark/                  # Flutter App
│   ├── lib/
│   │   ├── main.dart                   # Entry point + startup time measurement
│   │   ├── app.dart                    # App root & routing
│   │   ├── core/                       # Config, theme, utilities
│   │   ├── features/
│   │   │   ├── cpu_test/               # CPU benchmark screen & algorithm
│   │   │   ├── gpu_test/               # GPU/FPS/Memory/Battery test screen
│   │   │   └── home/                   # Home screen
│   │   ├── services/                   # Battery & memory MethodChannels
│   │   └── widgets/                    # Shared UI components
│   ├── ios/Runner/AppDelegate.swift    # Battery MethodChannel (native side)
│   └── pubspec.yaml
│
├── ios_benchmark/                      # Native iOS App (SwiftUI)
│   └── iOSBenchmark/
│       ├── iOSBenchmarkApp.swift       # Entry point + startup time measurement
│       ├── ContentView.swift           # Navigation
│       ├── CPUTestView.swift           # CPU benchmark
│       └── GPUTestView.swift           # GPU/FPS/Memory/Battery test
│
├── documentation/                      # Academic paper (LaTeX)
│   ├── paper.tex
│   └── refs.bib
│
├── screenshots/                        # App screenshots & demo media
├── presentation/                       # Presentation slides
├── README.md
└── TECHNICAL.md                        # Benchmark methodology & results analysis

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🧪 Test Specifications

Test 1: CPU Efficiency (Sieve of Eratosthenes)

Purpose: Measure raw single-thread computational performance.

Parameter	Value
Algorithm	Sieve of Eratosthenes
Range	2 to 1,000,000
Expected Result	78,498 primes
Thread	Main UI Thread (intentionally blocking)
Measurement	Execution time in microseconds

Scientific Rationale: Running on the main thread tests how each framework handles CPU-bound tasks and measures UI freezing behavior.

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Test 2 & 3: GPU/Memory Stress (List Scroll Test)

Purpose: Stress the GPU rasterizer and memory allocator.

Parameter	Value
List Items	1,000 complex items
Item Content	Gradient backgrounds, shadows, tags, buttons
Auto-Scroll Duration	30 seconds (constant velocity)
Scroll Curve	Linear (identical velocity on both platforms)

Measurements:

• FPS: Frame build times logged via SchedulerBinding (Flutter) / CADisplayLink (iOS)
• Jank Detection: Frames > 16.67ms (missing 60 FPS target)
• Memory: Monitored via Xcode Instruments / Flutter DevTools

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Test 4: Battery Impact

Purpose: Measure energy consumption during GPU stress.

Parameter	Value
Method	Battery level % before/after 30s scroll
Implementation	UIDevice.batteryLevel (iOS) / MethodChannel (Flutter)
Output	Delta percentage (e.g., "Battery Drain: 1%")

Note: Battery monitoring requires a physical device. Simulators return -1.

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Test 5: App Startup Time (TTI)

Purpose: Measure Time to Interactive.

Event	Flutter	iOS
Start	main() function called	@main app launch
End	addPostFrameCallback fires	.onAppear modifier
Measurement	Microseconds (μs)	Microseconds (μs)

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🚀 Running the Benchmarks

Flutter App

cd flutter_benchmark

# Get dependencies
flutter pub get

# Run in release mode for accurate benchmarks
flutter run --release

# Or profile mode for Flutter DevTools
flutter run --profile

iOS App

1. Open ios_benchmark/iOSBenchmark.xcodeproj in Xcode
2. Select a physical device (for battery metrics)
3. Build & Run (⌘R)
4. For performance profiling, use Product → Profile (⌘I)

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📈 Interpreting Results

Console Output

Both apps print detailed logs:

═══════════════════════════════════════════════
FLUTTER BENCHMARK - CPU TEST RESULTS
═══════════════════════════════════════════════
Algorithm: Sieve of Eratosthenes
Limit: 1000000
Primes found: 78498
Execution time: 45230 μs
Execution time: 45.23 ms
═══════════════════════════════════════════════

Key Metrics to Compare

Metric	Good	Acceptable	Poor
CPU Time	< 50ms	50-100ms	> 100ms
Jank Rate	< 1%	1-5%	> 5%
Est. FPS	≥ 58	50-58	< 50
Avg Frame Time	< 16.67ms	16.67-33ms	> 33ms

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🔬 Scientific Controls

To ensure valid comparison:

1. Same Device: Run both apps on the same physical device
2. Same Conditions: Close background apps, same battery state
3. Release Builds: Use release/production builds for both
4. Multiple Runs: Run each test 5+ times and average results
5. Cool-Down Period: Wait 1-2 minutes between tests to prevent thermal throttling

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📱 Requirements

Flutter

• Flutter SDK 3.10+
• Dart 3.0+
• iOS 12.0+ / Android API 21+

iOS Native

• Xcode 15.0+
• iOS 17.0+
• Swift 5.9+

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📝 License

MIT License - WISA Course Project