quant-recipe-search

name: quant-recipe-search description: >- Use when the user asks to find, search for, or optimize the best quantization recipe for a model, including direct requests like "find the best quantization recipe and generate a PTQ checkpoint." Guides the multi-candidate loop: choose compute-vs-memory success metrics, select ModelOpt recipe baselines, design AutoQuant/manual recipe deltas, interpret sensitivity, and decide next candidates. Do NOT use for a single known PTQ recipe run (use ptq), serving (use deployment), creating/running evals (use evaluation or launching-evals), monitoring jobs (use monitor), MLflow browsing (use accessing-mlflow), or comparing completed baseline-vs-candidate scores only (use compare-results).

Quant Recipe Search

Use this skill when quantization is an iterative recipe search, not a one-off PTQ run. The skill owns strategy: define success, choose the search space, sequence candidates, and decide the next iteration. It delegates checkpoint generation, serving, evaluation, monitoring, and metric comparison to the existing execution skills.

Treat a direct request such as "find the best quantization recipe and generate a PTQ checkpoint for this model" as enough to start. Recover local state first, then ask only for missing decisions that change the search.

Skill Boundaries

• Use ptq to produce and validate checkpoints.
• Use deployment to serve checkpoints and debug serving-specific flags.
• Use evaluation to create NEL configs and submit evals.
• Use launching-evals to run, resume, debug, and analyze NEL runs.
• Use monitor for active job tracking.
• Use accessing-mlflow for MLflow artifact lookup.
• Use compare-results for validated baseline-vs-candidate deltas and score-field comparability.

Do not duplicate those workflows here. This skill should leave the user with a clear recipe portfolio, success metric, experiment sequence, and next decision.

Problem

The task is to find the best recipe for a user-defined target, not merely to produce a quantized checkpoint. A generated PTQ checkpoint is only a candidate. It becomes a recommended recipe only after evaluation and comparison against the matching baseline.

Required inputs before planning candidates:

• Optimization goal: compute/throughput, memory/latency, or a custom metric.
• Primary quantization family: for example NVFP4, W4A16 NVFP4, FP8/W8A8, INT4/AWQ, or a custom mixed set.
• Benchmark set or baseline results: the user-defined acceptance surface.

If any of these are missing, ask for them. Do not silently default to FP8/W8A8 or call a checkpoint "best" before evaluation.

Default success rule: maximize the chosen performance objective while keeping each benchmark within 1 percentage point of the matching BF16/FP16 baseline. Near-threshold or noisy regressions require reruns before making a decision.

Search Space

Keep the search space explicit. A candidate recipe is a tuple across these axes:

• Numeric format: FP8/W8A8, NVFP4/W4A4, W4A16 NVFP4, INT4/AWQ, or mixed formats such as NVFP4+FP8.
• Calibration/search algorithm: max calibration, MSE calibration, GPTQ, AWQ, AutoQuant scoring, and calibration dataset or sample-count variants.
• Selection method: manual/heuristic rules, sensitivity-guided manual recipes, AutoQuant selection, or a hybrid of AutoQuant plus manual overrides.
• Module family: attention, MLP, MoE experts, routers/gates, embeddings, lm_head, adapters, vision encoders, and model-specific modules.
• Runtime fusion constraints: modules fused by the inference library must use compatible quantization. Examples: vLLM Qwen linear_attn.in_proj_qkvz and fused MoE expert projections such as gate/up (w1/w3).
• Calibration budget: dataset mix, sample count, sequence length, and batch settings.

Do not collapse the search to one dimension such as numeric format only. Read references/recipe_iteration.md when choosing concrete axes or candidates.

Design Workflow

1. Recover state

   • Read result tables, recipe logs, AutoQuant states, sensitivity reports, and experiment notes before proposing new work.
   • Ask monitor, launching-evals, or compare-results to recover active job state and completed metrics when needed.

2. Define the target

   • Confirm the optimization goal, primary quantization family, benchmark set, accuracy-loss threshold, calibration budget, and cost metric.
   • Include quantization metadata such as scale storage in active-cost or size estimates.

3. Pick baselines and first candidates

   • Always include BF16/FP16 and a near-lossless FP8/W8A8 baseline unless FP8 itself is the target.
   • For ModelOpt work, start from modelopt_recipes: model-specific recipes first, then general PTQ presets or recipe fragments.
   • Add an AutoQuant candidate in the requested primary family when AutoQuant is available. Expect AutoQuant to find a better trade-off than a first manual recipe, but validate that assumption with the same evals.
   • Add at least one manual or sensitivity-guided candidate so AutoQuant can be compared against controlled ablations and there is a fallback if AutoQuant misses the best frontier or hits runtime constraints.

4. Generate candidates

   • Delegate checkpoint generation and PTQ validation to ptq.
   • Change one major axis at a time: format, calibration algorithm, module selection, granularity, exclusions, or calibration data.
   • Use AutoQuant for broad candidate generation and sensitivity reports; use manual recipes for controlled module-family ablations and overrides.

5. Gate before scaling

   • Validate checkpoint coverage and metadata.
   • Reject or rewrite recipes that mix quantization algorithms inside a fused runtime group.
   • If the checkpoint is valid but serving fails due to runtime support, do not reject the recipe immediately. Delegate to deployment / debug for small patches or flags, then rerun a pipe-clean check.

Iteration Loop

1. Run cheap screen evals for every candidate that passes the gates.
2. Compare accuracy, verbosity/token usage, and active cost against baselines.
3. Rerun noisy or near-threshold results before labeling a regression.
4. Decide the next candidate:
   • Accuracy drop: protect or ablate sensitive module families, try MSE/GPTQ, or use AutoQuant sensitivity to choose overrides.
   • Poor performance/cost: quantize the next high-cost active family, adjust active-cost objective, or try a more aggressive format.
   • AutoQuant underperforms manual recipes: inspect sensitivity reports, achieved bits, excluded modules, and runtime-fusion constraints; keep the manual recipe in the portfolio instead of forcing the AutoQuant result.
   • Runtime incompatibility: rewrite around fused groups or isolate deployment support from checkpoint quality.
   • Repeated AutoQuant recipes: inspect achieved bits and recipe hashes, then adjust constraints before launching a larger sweep.
5. Promote only when compare-results shows the candidate is comparable to the baseline and satisfies the user-defined goal.

Maintain a recipe portfolio table with recipe name, objective, active-cost estimate, calibration notes, checkpoint path, eval/log references, accuracy, verbosity, and decision.

References

• For recipe design, search-space details, sensitivity, and active-cost accounting, read references/recipe_iteration.md.
• For a concrete prior case study, read references/qwen36_case_study.md only when Qwen3.5/Qwen3.6 details are relevant.