spb/localvm-research Public License
Running LLMs larger than memory on a consumer Mac — falsification-driven research: margin-gated deferred refinement, out-of-core verification on Apple Silicon. TR-01 published.
Python 63.2%
JavaScript 23.5%
CSS 11.8%
Shell 0.9%
Makefile 0.5%
1#!/usr/bin/env python32# =============================================================================3# Project : localvm-research4# File : experiments/candidate_01/benchmark.py5# Purpose : End-to-end evaluation of the margin-gated deferred-refinement6# runtime vs pure-q4 / pure-q8 baselines7# Author : Simon-Pierre Boucher8# Contact : contact@spboucher.ai9# Created : 2026-08-1210# Modified : 2026-08-1211# Platform : macOS / Apple Silicon (arm64) — MLX / Metal12# License : All rights reserved (research code)13# =============================================================================14"""Candidate-01 benchmark.1516Build once (downloads + quantizes):17 .venv/bin/python benchmark.py --build18Run:19 .venv/bin/python benchmark.py [--per-domain 4] [--max-tokens 128]20 [--window 32] [--taus 1.0,2.0]21"""2223from __future__ import annotations2425import argparse26import difflib27import json28import sys29import time30from datetime import datetime, timezone31from pathlib import Path3233import mlx.core as mx34from mlx_lm import load3536REPO_ROOT = Path(__file__).resolve().parents[2]37sys.path.insert(0, str(REPO_ROOT / "benchmarks"))38sys.path.insert(0, str(Path(__file__).parent / "implementation"))39from hardware_manifest import collect_manifest # noqa: E40240from runtime import generate_deferred # noqa: E4024142MODELS_DIR = Path(__file__).parent / "implementation" / "models"43HF_MODEL = "mlx-community/Qwen3-1.7B-bf16"444546def build() -> None:47 from mlx_lm import convert4849 for bits in (4, 8):50 out = MODELS_DIR / f"q{bits}"51 if out.exists():52 print(f"{out} exists, skipping")53 continue54 print(f"converting {HF_MODEL} → q{bits} …", flush=True)55 convert(HF_MODEL, mlx_path=str(out), quantize=True, q_bits=bits, q_group_size=64)56 print("build done")575859def dir_weight_bytes(d: Path) -> int:60 return sum(f.stat().st_size for f in d.glob("*.safetensors"))616263def greedy_baseline(model, tokenizer, prompt_ids, max_tokens):64 from mlx_lm.models.cache import make_prompt_cache6566 cache = make_prompt_cache(model)67 tokens = []68 inp = mx.array(list(prompt_ids))[None]69 t0 = time.perf_counter()70 for _ in range(max_tokens):71 logits = model(inp, cache=cache)72 nxt = int(mx.argmax(logits[0, -1]).item())73 if nxt == tokenizer.eos_token_id:74 break75 tokens.append(nxt)76 inp = mx.array([[nxt]])77 return tokens, time.perf_counter() - t0787980def judge_outputs(outputs_by_config: dict, prompts: list[dict]) -> dict:81 """Quality-level metric: mean per-token logprob of each config's generated82 continuation under the bf16 reference model (higher = better). Token-exact83 fidelity is incoherent on Metal (1.56%/token prefill/decode flips), so the84 judge scores usefulness of the text the system actually produced."""85 import gc8687 gc.collect(); mx.clear_cache()88 judge, _ = load(HF_MODEL)89 scores = {}90 for name, outs in outputs_by_config.items():91 vals = []92 for p, toks in zip(prompts, outs):93 if len(toks) < 2:94 continue95 full = p["ids"] + list(toks)96 logits = judge(mx.array(full)[None])[0]97 sel = logits[len(p["ids"]) - 1 : len(full) - 1].astype(mx.float32)98 logprobs = sel - mx.logsumexp(sel, axis=-1, keepdims=True)99 idx = mx.array(toks)100 tok_lp = mx.take_along_axis(logprobs, idx[:, None], axis=-1)101 mx.eval(tok_lp)102 vals.append(float(mx.mean(tok_lp).item()))103 scores[name] = {"mean_logprob_bf16": sum(vals) / len(vals), "n": len(vals)}104 del judge105 gc.collect(); mx.clear_cache()106 return scores107108109def fidelity(a: list[int], b: list[int]) -> float:110 """Similarity of two token sequences (difflib ratio — robust to length111 drift after divergence)."""112 if not a and not b:113 return 1.0114 return difflib.SequenceMatcher(None, a, b).ratio()115116117def main() -> None:118 ap = argparse.ArgumentParser()119 ap.add_argument("--build", action="store_true")120 ap.add_argument("--per-domain", type=int, default=4)121 ap.add_argument("--max-tokens", type=int, default=128)122 ap.add_argument("--window", type=int, default=32)123 ap.add_argument("--taus", default="1.0,2.0")124 args = ap.parse_args()125 if args.build:126 build()127 return128129 domains = json.loads((REPO_ROOT / "benchmarks/datasets/eval_prompts.json").read_text())["domains"]130 q4_dir, q8_dir = MODELS_DIR / "q4", MODELS_DIR / "q8"131 q8_bytes = dir_weight_bytes(q8_dir)132 q4_bytes = dir_weight_bytes(q4_dir)133 print(f"resident q4: {q4_bytes/1e9:.2f} GB · streamed q8: {q8_bytes/1e9:.2f} GB", flush=True)134135 base_model, tokenizer = load(str(q4_dir))136 verify_model, _ = load(str(q8_dir))137138 prompts = []139 for domain, plist in domains.items():140 for prompt in plist[: args.per_domain]:141 ids = tokenizer.apply_chat_template(142 [{"role": "user", "content": prompt}], add_generation_prompt=True)143 prompts.append({"domain": domain, "ids": list(ids)})144145 # baselines146 print("baseline: pure q8 greedy …", flush=True)147 q8_out, q8_times = [], []148 for p in prompts:149 toks, dt = greedy_baseline(verify_model, tokenizer, p["ids"], args.max_tokens)150 q8_out.append(toks); q8_times.append((len(toks), dt))151 print("baseline: pure q4 greedy …", flush=True)152 q4_out, q4_times = [], []153 for p in prompts:154 toks, dt = greedy_baseline(base_model, tokenizer, p["ids"], args.max_tokens)155 q4_out.append(toks); q4_times.append((len(toks), dt))156157 def toks_per_s(times):158 n = sum(t for t, _ in times); s = sum(d for _, d in times)159 return n / s if s else 0.0160161 configs = []162 for mode in ("margin", "verify-all"):163 for tau in ([float(x) for x in args.taus.split(",")] if mode == "margin" else [2.0]):164 configs.append({"mode": mode, "tau": tau})165166 outputs_by_config = {"pure_q4": q4_out, "pure_q8": q8_out}167 results = []168 for cfg in configs:169 print(f"runtime: mode={cfg['mode']} tau={cfg['tau']} W={args.window} …", flush=True)170 fid, agg = [], {"tokens": 0, "deferred": 0, "sweeps": 0, "rollbacks": 0,171 "sweep_s": 0.0, "gen_s": 0.0, "logical_bytes": 0}172 cfg_outputs = []173 for p, ref in zip(prompts, q8_out):174 toks, st = generate_deferred(175 base_model, verify_model, tokenizer, p["ids"],176 args.max_tokens, cfg["tau"], args.window, cfg["mode"], q8_bytes)177 cfg_outputs.append(toks)178 fid.append(fidelity(toks, ref))179 agg["tokens"] += st.tokens_out; agg["deferred"] += st.deferred180 agg["sweeps"] += st.sweeps; agg["rollbacks"] += st.rollbacks181 agg["sweep_s"] += st.sweep_time_s; agg["gen_s"] += st.gen_time_s182 agg["logical_bytes"] += st.sweep_logical_bytes183 n = max(agg["tokens"], 1)184 results.append({185 **cfg, "window": args.window,186 "fidelity_vs_q8_mean": sum(fid) / len(fid),187 "tokens_per_s": n / (agg["gen_s"] + agg["sweep_s"]),188 "deferral_rate": agg["deferred"] / n,189 "rollback_rate": agg["rollbacks"] / n,190 "sweeps_per_100tok": 100 * agg["sweeps"] / n,191 "sweep_latency_s_mean": agg["sweep_s"] / max(agg["sweeps"], 1),192 "logical_verify_bytes_per_token": agg["logical_bytes"] / n,193 "raw": agg,194 })195 outputs_by_config[f"{cfg['mode']}_tau{cfg['tau']}"] = cfg_outputs196 r = results[-1]197 print(f" fidelity={r['fidelity_vs_q8_mean']:.4f} tok/s={r['tokens_per_s']:.1f} "198 f"defer={r['deferral_rate']:.2f} rollback={r['rollback_rate']:.3f} "199 f"MB/token(logical)={r['logical_verify_bytes_per_token']/1e6:.0f}", flush=True)200201 print("judging outputs with bf16 reference …", flush=True)202 quality = judge_outputs(outputs_by_config, prompts)203 for name, s in quality.items():204 print(f" {name:>18}: mean logprob (bf16 judge) = {s['mean_logprob_bf16']:.4f}", flush=True)205206 payload = {207 "experiment": "candidate_01_deferred_refinement",208 "author": "Simon-Pierre Boucher",209 "contact": "contact@spboucher.ai",210 "manifest": collect_manifest(),211 "config": vars(args),212 "model": HF_MODEL,213 "q4_resident_bytes": q4_bytes, "q8_stream_bytes": q8_bytes,214 "baselines": {215 "pure_q4": {"tokens_per_s": toks_per_s(q4_times),216 "fidelity_vs_q8_mean": sum(fidelity(a, b) for a, b in zip(q4_out, q8_out)) / len(q8_out)},217 "pure_q8": {"tokens_per_s": toks_per_s(q8_times), "fidelity_vs_q8_mean": 1.0},218 },219 "runs": results,220 "quality_bf16_judge": quality,221 }222 ts = datetime.now(timezone.utc).strftime("%Y%m%dT%H%M%SZ")223 out_dir = REPO_ROOT / "results" / "candidate_01" / ts224 out_dir.mkdir(parents=True)225 (out_dir / "results.json").write_text(json.dumps(payload, indent=2))226 print(f"\nwrote {out_dir / 'results.json'}")227 print("baselines:", json.dumps(payload["baselines"], indent=1))228229230if __name__ == "__main__":231 main()232