PERFORMANCE.md

Nerviq Performance Baselines

Baseline measurements for nerviq audit on an empty (no config files) repository. All measurements taken on the CI/benchmark machine using src/audit.js directly (bypassing CLI process spawn overhead of ~80-120ms).

Method

const dir = fs.mkdtempSync(os.tmpdir() + '/perf-');
const { audit } = require('./src/audit');
const t0 = performance.now();
await audit({ dir, platform, silent: true });
const elapsed = performance.now() - t0;
fs.rmSync(dir, { recursive: true, force: true });

3 warm runs, median reported. Node.js v18+. No external network calls.

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Platform Baselines (empty repo, in-process)

Platform	p50 (ms)	p95 target	Budget
claude	~70	< 500	< 5000
codex	~80	< 500	< 5000
cursor	~75	< 500	< 5000
gemini	~75	< 500	< 5000
copilot	~70	< 500	< 5000
windsurf	~70	< 500	< 5000
aider	~80	< 500	< 5000
opencode	~80	< 500	< 5000

Note: Numbers above are for the in-process audit() call. Add ~100–150ms for CLI process-spawn overhead when calling via node bin/cli.js.

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CI Process-Spawn Baselines (via node bin/cli.js)

These include Node.js startup + require() time.

Platform	p50 (ms)	Notes
claude	~200	Includes Node.js startup
codex	~260
cursor	~200
gemini	~225
copilot	~200
windsurf	~200
aider	~245
opencode	~260

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Regression Thresholds

Tier	Threshold	Action
CI fast-gate	5 000 ms (5s)	Fail CI — something is seriously wrong
Warning	1 000 ms (1s)	Alert in PR — investigate before merge
Target	500 ms	Ideal for local developer experience
In-process target	200 ms	Goal for audit() API call

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Optimization Notes

1. Module loading is the dominant cost — require() chains for all 8 platform technique modules fire on first audit. Cold-start overhead is ~50–80ms.
2. File system reads — empty repo = minimal I/O. Rich repos with many config files add 5–20ms for context construction.
3. No async I/O — all context reads are synchronous fs.readFileSync calls, bounded by file count.
4. Techniques evaluation — O(n) over check count. 88 cursor checks + 71 aider checks etc., all synchronous, typically < 10ms total.

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Historical Snapshots

Date	Version	claude p50	codex p50	Notes
2026-04-05	0.9.4	~70ms	~80ms	Baseline measurement

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Last updated: 2026-04-05 Measured on: Node.js v18+, Windows 11