sage-quant 0.2.1

SageQuant: Open-source inference tradeoff calculator and quantization advisor

SageQuant is a data-driven CLI tool that helps you choose the optimal serving stack. Given your model size, target hardware, workload shape, and tail latency/quality budget, it recommends the best inference engine, quantization algorithm, and bit-width scheme.

It provides choices backed by real benchmark data, not guesswork.

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Why SageQuant?

Choosing how to serve an LLM today is usually an ad-hoc decision: defaulting to vLLM, trying AWQ w4a16 because of a blog post, and hoping for the best.

SageQuant replaces this guesswork with a structured lookup across three distinct decisions:

1. Inference Engine: vLLM vs. SGLang vs. TensorRT-LLM vs. MLX
2. Quantization Algorithm: GPTQ vs. AWQ vs. FP8 vs. SmoothQuant vs. MLX native
3. Bit-width Scheme: FP16 vs. 8-bit (W8A8) vs. 4-bit (W4A16)

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Tradeoff Visualization

SageQuant maps tradeoffs across engines and algorithms for the same model and hardware:

Engine	Quant Algo	Scheme	TTFT (p50 / p95)	Throughput	Quality vs. FP16
vLLM	none	fp16	85 / 140ms	45.0 tok/s	baseline
vLLM	GPTQ	w4a16	145 / 210ms	38.2 tok/s	-1.1% (mmlu-5shot, n=200)
vLLM	AWQ	w4a16	140 / 205ms	39.5 tok/s	-0.8% (mmlu-5shot, n=200)
SGLang	AWQ	w4a16	98 / 165ms	52.0 tok/s	-1.4% (mmlu-5shot, n=200)

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Quick Start

1. Install

pip install -e .
# Advanced features (Streamlit dashboard & scikit-learn regression interpolation):
pip install -e ".[advanced]"

2. Get a Recommendation

Find the best stack based on your budget:

sage-quant recommend --model-size 7b --hardware a100-40gb --max-latency 200ms --min-quality 98

Recommended: SGLANG + AWQ (w4a16), prefix caching on
Workload: 128 in / 128 out tokens
Expected: 60ms TTFT (p50) · 105ms TTFT (p95) · 75.0 tok/s · -1.4% quality (mmlu-5shot, n=200)
Confidence: exact (3 matching benchmark runs)

Note (Engine): SGLang features RadixAttention and is highly efficient for high-cache-reuse workloads.
Note (Algo): AWQ generally preserves quality slightly better than GPTQ at 4-bit.

3. Generate Serving Config

Get a copy-pasteable server launch command:

sage-quant serve-config --model-size 7b --hardware a100-40gb --model meta-llama/Meta-Llama-3-8B-Instruct --prefer-engine sglang

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Command Reference

• sage-quant recommend — Find optimal engine, algorithm, and scheme. Supports --prompt-tokens, --output-tokens, and --prefer-engine.
• sage-quant serve-config — Generate vLLM/SGLang/MLX launch configuration scripts or YAML files.
• sage-quant list-hardware / list-engines / list-quant-algos — Check what combinations are currently covered in the dataset.
• sage-quant contribute — Append custom benchmark runs (JSON/CSV) to the local dataset and get instructions to open a PR.

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Documentation

For a comprehensive guide, detailed command usage, and real-world example scenarios, see the User Guide.

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License

MIT