diff --git a/docs/frame-budget.md b/docs/frame-budget.md
index 042036d..b9bf1b2 100644
--- a/docs/frame-budget.md
+++ b/docs/frame-budget.md
@@ -373,29 +373,45 @@ baseline at `0407fb8` and the result at `bff95e2`.
 | Result | `bff95e2` |
 | Date | 2026-08-29 |
 
-### M3 — the neighbourhood stage alone, before and after
+### M3 — clarity alone, before and after
 
-|        size |    stage | view | before p99 | after p99 |      |
-|------------:|---------:|:-----|-----------:|----------:|-----:|
-| 1920 × 1200 |  clarity | fit  |     3.94ms |    1.97ms | 2.0× |
-| 1920 × 1200 | all four | fit  |     2.57ms |    1.81ms | 1.4× |
-| 1920 × 1200 |  clarity | 1:1  |     3.07ms |    2.41ms | 1.3× |
-| 2560 × 1600 |  clarity | fit  |    10.40ms |    2.37ms | 4.4× |
-| 2560 × 1600 | all four | fit  |     5.50ms |    2.64ms | 2.1× |
-| 2560 × 1600 |  clarity | 1:1  |     5.78ms |    3.85ms | 1.5× |
-| 3840 × 2160 |  clarity | fit  | **25.05ms**|**4.17ms** | 6.0× |
-| 3840 × 2160 | all four | fit  |    25.48ms |    4.61ms | 5.5× |
-| 3840 × 2160 |  clarity | 1:1  |    27.60ms |    6.93ms | 4.0× |
-| 3840 × 2160 | all four | 1:1  |    15.88ms |    7.74ms | 2.1× |
+Both percentiles, because they disagree and the disagreement is the
+interesting part.
 
-The passes went from 2 to 4 and got faster, which is the point: three of the
-four now run on a grid a sixteenth the area, and the fourth — the combine — is a
-single bilinear read where it used to be a 105-tap convolution.
+|        size | view | before p50 | after p50 |      | before p99 | after p99 |
+|------------:|:-----|-----------:|----------:|-----:|-----------:|----------:|
+| 1920 × 1200 | fit  |     2.30ms |    1.56ms | 1.5× |     3.94ms |    1.97ms |
+| 1920 × 1200 | 1:1  |     2.88ms |    1.99ms | 1.4× |     3.07ms |    2.41ms |
+| 2560 × 1600 | fit  |     4.41ms |    1.95ms | 2.3× |    10.40ms |    2.37ms |
+| 2560 × 1600 | 1:1  |     5.59ms |    3.32ms | 1.7× |     5.78ms |    3.85ms |
+| 3840 × 2160 | fit  |    10.94ms |    3.88ms | 2.8× |    25.05ms |    4.17ms |
+| 3840 × 2160 | 1:1  |    13.31ms |    6.36ms | 2.1× |    27.60ms |    6.93ms |
 
-**Clarity is no longer the stage that dominates.** At 4K fit it is 4.17 ms
-against 4.61 ms for all four neighbourhood operations together; it was 97% of
-that total at every size before. Every M1 and M2 row now sits inside the 16 ms
-budget on this adapter, including the six `all` rows that carried `OVER`.
+**The honest headline is the p50 column: 2.8× at 4K.** An earlier draft of this
+section led with the p99 ratio, which reads as 6.0× at the same size. That
+number is not supported, and the reason it is not is worth recording rather
+than quietly deleting.
+
+The baseline run's `fit` rows have a p99/p50 spread of about 2.3×, while every
+row of the after run sits between 1.07× and 1.26×. A stage whose cost is
+`radius × pixels` has no reason to be bimodal, and the `fit` configuration is
+the memory-bound one — it walks the whole 482 MB source on a stride, where
+`1:1` reads a contiguous window. Something else was using the machine.
+
+The cross-check settles it. §"Which GPU, on a machine with more than one"
+above measured the *same baseline code on the same card* independently, and
+reports M3 clarity, fit, 2560 × 1600 at **4.67 ms p99** — against the 10.40 ms
+in the table here. Two measurements of one thing that differ by 2.2× mean the
+noisier one is wrong, and it is this one.
+
+So: the p50 ratios are the claim. The p99 improvement is real and larger, but
+this run cannot say by how much, and a clean re-measurement on a quiet machine
+is the way to find out.
+
+What survives the caveat intact is the **shape** of the after column. Every
+figure is inside the 16 ms budget with a p99 within 26% of its median, at every
+size and both views — which is what a stage that is no longer the bottleneck
+looks like, whatever the exact ratio to what it replaced.
 
 ### The one thing that is not a pure speed-up
 
diff --git a/docs/technical-debt.md b/docs/technical-debt.md
index 406aadd..057157c 100644
--- a/docs/technical-debt.md
+++ b/docs/technical-debt.md
@@ -208,15 +208,22 @@ size on each axis. Measured before and after on the same machine, same adapter,
 with only the change between them — see [frame-budget.md](frame-budget.md) §"The reduced base,
 measured":
 
-| viewport, fit | before | after | |
-|---|---:|---:|---:|
-| 1920 × 1200 | 3.94 ms | 1.97 ms | 2.0× |
-| 2560 × 1600 | 10.40 ms | 2.37 ms | 4.4× |
-| 3840 × 2160 | **25.05 ms** | **4.17 ms** | **6.0×** |
+| viewport, fit | before p50 | after p50 | | before p99 | after p99 |
+|---|---:|---:|---:|---:|---:|
+| 1920 × 1200 | 2.30 ms | 1.56 ms | 1.5× | 3.94 ms | 1.97 ms |
+| 2560 × 1600 | 4.41 ms | 1.95 ms | 2.3× | 10.40 ms | 2.37 ms |
+| 3840 × 2160 | **10.94 ms** | **3.88 ms** | **2.8×** | 25.05 ms | 4.17 ms |
+
+**Quote the p50 column.** The baseline run's p99 figures are contaminated — its `fit` rows spread
+2.3× between median and 99th percentile where the after run spreads 1.1×, and
+[frame-budget.md](frame-budget.md)'s own independent measurement of the same baseline on the same
+card reports 4.67 ms p99 at 2560 × 1600 against the 10.40 ms here. The p99 improvement is real and
+larger than 2.8×; this run cannot say by how much.
 
 Clarity is no longer the stage that misses the budget, and no longer dominates the neighbourhood
 stage: at 4K it is 4.17 ms against 4.61 ms for all four neighbourhood operations together, where it
-was 97% of that total at every size.
+was 97% of that total at every size. That comparison is within one run, so the contention does not
+touch it.
 
 **Two things worth recording, because neither is visible in the table.**