diff --git a/docs/bench-log.md b/docs/bench-log.md
index ea9a8633e..1731737b6 100644
--- a/docs/bench-log.md
+++ b/docs/bench-log.md
@@ -1607,3 +1607,21 @@ Reading: the kernel is the same 116.0 ms on both paths (18.08 MH/s pure kernel,
 **A second defect found on the way: the pack export race.** PC 1's app log since its 19:02 UTC restart (`node tools/logs.mjs win-ae432dc7-20261005-190232`): `worker error: error 0 pack packs\devnet: the epoch seed bytes do not give the pack's IGNEUM_SEEDW_INIT` at 19:07:03, 19:07:19 and 19:08:07, so the 9070 XT was not mining at all in the app while this entry was written (my job `rdna4-serve-1` at 18:43 hit the same folder in the same state). Cause, from `app/igneum-app/src/engine.rs` `prepare_worker`: one thread per card, each running `igneum-miner export-pack` into the one folder `packs\devnet`; across an epoch change the two exports interleave and the folder keeps one epoch's `program.h` with the other's `seeds.txt` until the next export. Fix on this branch: a process-wide mutex around both export sites (`EXPORT_LOCK`); the second export rewrites the same pack. Not measured in the app yet: it ships with the branch.
 
 **Answer to the project lead.** The 9070 XT does 2.5 G random 4-byte reads per second from its memory for this access pattern, and the hash needs 128 of them, so about 19 MH/s is this card's ceiling for the current program class, on any slot; it was running at 92% of that. The eGPU link cost 6% per job through the read-back, now removed (17.87 against 16.88 MH/s inside jobs standalone). The duplicate platform that halved it to 8.9 + 9.4 is folded away. The pack race that stopped it is serialised. Nothing else in the worker's control moves the number: the next step for this card is the program class itself (fewer, wider loads per hash would favour AMD's 64-byte lines), which is a consensus question, not a worker one.
+
+## 5 October 2026 (night), Ember Tune: the two-knob efficiency tune, the fleet prior, and what PC 1 could measure tonight (miner-community-lead)
+
+Branch `ember-tune` (54ff1bc), docs/plans/ember-tune.md. Every card tuned for MH per watt out of the box: the power limit and the core clock cap stepped on the live kernel (memory clock never touched), the point with the best MH per watt within 1% of the top rate kept and pinned, every result uploaded as a `TUNE {json}` record (a hash of the install id, no address) and folded per (card model, driver major, program class) into a prior the signed manifest carries back, so a new card of a known model starts there and confirms it in two steps.
+
+**What was measured tonight (PC 1, machine ae432dc7, from its own uploads to the intake):**
+
+| Fact | Where it was read | Consequence |
+|---|---|---|
+| The installed 0.3.9 app runs as `DESKTOP-KMCV30N\Admin` with `elevated=False` (account line, 19:02:33 UTC) | app log `win-ae432dc7-20261005-190232` | `nvidia-smi -pl` and `-lgc` need administrator rights; the one prompt is the Power control switch (3562f26), which the app never raises by itself |
+| Two in-app sweep attempts aborted at 20:09 UTC: `the_elevated_helper_did_not_run_(the_administrator_prompt_was_cancelled)` | the same log | no stored sweep result from today exists; the 5090's two-knob tune is owed to the morning (one click on Power control, then it runs by itself within 2 minutes of steady mining) |
+| The RX 9070 XT left PC 1's bus at about 20:40 UTC, was back at 21:09 and gone again at 21:22:59 UTC (the eGPU link, third drop today) | the telemetry agent and the PC 1 scheduler | the AMD path (ADLX, no prompt) is unit-tested on the helper's captured line shapes; its end-to-end run waits for the card |
+
+**The pipeline, verified without a card:** 9 `ember` unit tests (plans, clamps, the choice rule, the five marks, a faulted step reverted inside a fake-clock run, the confirm verdicts, the baseline plan, the record and prior shapes, the vendor reasons), the AMD `tune` line and the 0.3.10 sample line parsed (`engine::amd_telemetry_tests`), the helper protocol (`sweep::tests`), 6 relay aggregation tests (five samples converge on 2,470 MHz at 100%; an outlier at 0.908 MH/W moves the median by nothing; baseline records make no prior; de-duplication; the manifest merge keeps lever 2's cards; the canonical round trip), 3 UI line tests. A test manifest was signed on this Mac with `packaging/ota/publish-manifest.sh --tuning` from fixture priors: `tuning.priors["NVIDIA_GeForce_RTX_5090|581|l128w16"]` = 2,470 MHz at 100%, 5 samples, beside the kernel-variant `cards` entry and `tuning.ember {enabled: true, min_samples: 5, rate_tolerance_pct: 1}`, signature verified by the signer, 21:25 UTC.
+
+**Tier consequences** (docs/plans/ember-tune.md section 7): a 9-step full tune costs about 12 minutes once and 3 minutes a week per card, under 1% of the hour, the worker never stops; a rig tunes one card at a time and every card of a known model after the first takes the 3-minute confirm; a pool user gives up the same 1% of shares at most; Apple silicon and AMD on Linux measure only and the row says so.
+
+(The PC 1 run's numbers follow below when the job reports.)