Dot performance dashboard

Warm, in-process timing of graphviz-ts vs the native dot oracle over the dot test corpus. Peer to PARITY.md — PARITY tracks correctness, PERF tracks speed. A report, not a gate. The fidelity target is ≤3× native.

Regenerate: npm run build:js && node test/corpus/bench.mjs && node test/corpus/perf-dashboard.mjs.

Method

• Port: the shipped bundle (dist/index.js) loaded once in a pool of resident, JIT-primed worker threads; pure renderSvg() is timed (best-of-N), so the measured region excludes all process/transpile/module-load startup — the warm steady state a long-lived consumer sees. Light graphs run at full pool; heavy graphs (native > 2s) are timed serially by default — measured cross-talk inflates a concurrent big render's single sample materially (≈66% on 2620). Set BENCH_HEAVY_POOL>1 for a faster, noisier scan.
• Native: dot -Tsvg best-of-3 (min).
• Budget: target ≤3× native. Per-render cap 817795ms (SIGKILL → over-cap, i.e. a true synchronous hang).
• Caveat: light graphs are timed under up-to-6-way load; for a precise single number re-run BENCH_POOL=1 BENCH_IDS=<id> node test/corpus/bench.mjs.

Summary

• Rated inputs: 778 · within ≤3× native: 762 (97.9%)
• ok (≤3×): 762 · slow (>3×): 16 · over-cap (hang): 1 · errored: 0 · oracle-error: 11
• ratio (port/native): p50 0.01× · p90 0.17× · max 6.18×

Ratio distribution

band	count
≤1× (port ≥ native, warm)	737
1–2×	15
2–3×	10
3–4×	15
4–6×	0
6–10×	1
>10×	0
over-cap (≥817795ms, possible hang)	1

Over budget — slower than 3× native (worst first)

id	native ms	port ms (warm)	ratio
2108	12849	79370	6.18×
graphs-b104	8635	33395	3.87×
graphs-b100	8646	31228	3.61×
2743	201	704	3.5×
nshare-root_circo	247	865	3.5×
2646	97463	337497	3.46×
graphs-b103	1210	4109	3.4×
linux.x86-root_twopi	248	834	3.36×
graphs-root	214	712	3.33×
2095_1	22309	73128	3.28×
linux.x86-root_circo	245	798	3.26×
2620	371	1153	3.11×
nshare-root_twopi	247	768	3.11×
graphs-badvoro	320	991	3.1×
2095	261	794	3.04×
graphs-b29	585	1773	3.03×

Over-cap / possible hang

id	native ms	cap ms	native×budget	status
2854	163559	817795	490677	exceeds budget (likely hang/runaway)

Raise BENCH_CAP_MS and re-run these ids to resolve an inconclusive status.