A person's page (and every face confirmed there) compares each unnamed
face with each of the person's named faces on the UI thread, on one core:
92 000 unnamed faces against 4 100 named ones is some 400 million
512-long dot products, about 2 min 40 s on an Apple M1 Pro with the
window frozen.
- matching::cosine sums in eight lanes, which the compiler vectorizes
(about 4x faster on 512-long embeddings; same result to the last bits).
- matching::person_score: one person's score as rank gives it, with no
names to group by and nothing allocated (same score, tested).
- similar() scores the candidates with rayon: about 3 s in the same case
(benchmark at that scale: 163 s before, 3 s after).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
