Bitstream Index Formula
A practical metric for evaluating AI model deployability
Bitstream Index = (Throughput × Memory Efficiency) / Load Time
Where:
• Load Time = Model Size ÷ Device Bandwidth
• Memory Efficiency = 1 - (Model Size ÷ Device Memory)
• Throughput = min(Device Ops, Required Ops) ÷ Required Ops
Why Bitstream Index?
Parameter count alone doesn't tell you if a model will actually run on your hardware. Bitstream Index considers file size, memory constraints, bandwidth, and compute capability to give you a realistic performance score.
Interpretation
- • Higher scores = Better device compatibility
- • Score of 0 = Model won't fit in memory
- • >100 = Excellent performance expected
- • 50-100 = Good performance, may have limitations
- • <50 = Marginal performance, consider optimization
AI Models
Add models to benchmark against device constraints
GPT-3.5-Turbo
GGUF • Q4_0 • 4,096 MB
7.0B parameters
LLaMA-2-13B
GGUF • Q4_0 • 8,192 MB
13.0B parameters
Mistral-7B
GGUF • Q5_0 • 3,584 MB
7.3B parameters
Device Constraints
Select or customize device specifications
High-End Desktop
Memory:32,000 MB
Bandwidth:800 MB/s
Operations:40,000 GFLOPS
Gaming Laptop
Memory:16,000 MB
Bandwidth:400 MB/s
Operations:15,000 GFLOPS
Standard Laptop
Memory:8,000 MB
Bandwidth:200 MB/s
Operations:5,000 GFLOPS
Mobile (Flagship)
Memory:8,000 MB
Bandwidth:50 MB/s
Operations:2,000 GFLOPS
Mobile (Mid-Range)
Memory:4,000 MB
Bandwidth:25 MB/s
Operations:800 GFLOPS
Edge Device / IoT
Memory:512 MB
Bandwidth:10 MB/s
Operations:100 GFLOPS
Performance Analysis
Side-by-side comparison of Bitstream Index scores
Bitstream Index Comparison
Compare model performance across different device constraints
| Model | Size (MB) | High-End Desktop | Gaming Laptop | Standard Laptop | Mobile (Flagship) | Mobile (Mid-Range) | Edge Device / IoT |
|---|---|---|---|---|---|---|---|
| GPT-3.5-Turbo | 4,096 | 0.5 | 0.1 | 0.0 | 0.0 | N/A | N/A |
| LLaMA-2-13B | 8,192 | 0.1 | 0.0 | N/A | N/A | N/A | N/A |
| Mistral-7B | 3,584 | 0.5 | 0.1 | 0.0 | 0.0 | 0.0 | N/A |
Bitstream Index by Model
Higher scores indicate better device compatibility
Load Time Comparison
Time to load model into device memory (seconds)
Model Size Distribution
Relationship between model size and Bitstream Index scores