From 17b6631310dd35f5a4322bd14c14fc3e7053496d Mon Sep 17 00:00:00 2001 From: Julien Calixte Date: Sat, 11 Jul 2026 17:21:26 +0200 Subject: [PATCH] docs(qfd): annotate H7 Publish latency with measured :sync data MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Adds a ‡ footnote on H7 (mirroring the H4 boot-latency †): cold :sync ~16 s / warm ~10 s measured 2026-07-11 — within the ≤30 s v0.1 target, marginal against the ≤10 s v1.0 target (cold's one-time Wi-Fi+SNTP push it over). Links the breakdown in notes/sync-latency.md. --- docs/qfd.md | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/docs/qfd.md b/docs/qfd.md index 0fe69bf..e460b76 100644 --- a/docs/qfd.md +++ b/docs/qfd.md @@ -86,7 +86,7 @@ inside HOW names: **Render** (buffer → e-ink frame, inside Type), | H4 | Boot latency (cold) | ↓ | ≤ 5 s | ≤ 3 s † | | H5 | Continuous-typing endurance (no drop, no leak) | ↑ | ≥ 1 h | ≥ 8 h | | H6 | Publish reliability (network up) | ↑ | ≥ 95 % | ≥ 99 % | -| H7 | Publish latency (one file) | ↓ | ≤ 30 s | ≤ 10 s | +| H7 | Publish latency (one file) | ↓ | ≤ 30 s ‡ | ≤ 10 s ‡ | | H8 | Save durability (post-confirm power loss) | → | 100 % | 100 % | | H9 | PSRAM heap headroom during Publish | ↑ | ≥ 1 MB free at peak | same | | H10 | Firmware binary size | ↓ | ≤ 2 MB | ≤ 1.5 MB | @@ -101,6 +101,14 @@ one ~1.9 s full refresh is unavoidable at cold boot (the `0x26` "previous" bank garbage until the first full paint), an e-ink floor rather than a tuning knob. Breakdown + levers: [`notes/boot-time-budget.md`](notes/boot-time-budget.md). +‡ **Publish latency, measured 2026-07-11:** a cold `:sync` is **~16 s** (warm +**~10 s**), comfortably inside the ≤ 30 s v0.1 target. The ≤ 10 s v1.0 target is +**marginal** — the warm path meets it, but a cold sync's one-time Wi-Fi assoc +(~3.6 s) + SNTP (~2–4 s) push it over, and the transport itself (one TLS handshake ++ commit + push) is near its floor. Optimistic-retry (push onto the tip first, +reconcile only on a rejected push) already cut a whole second handshake. Breakdown ++ levers: [`notes/sync-latency.md`](notes/sync-latency.md). + --- ## 3. House of Quality — WHATs × HOWs