diff --git a/docs/PERFORMANCE.md b/docs/PERFORMANCE.md
index 3ddd181..3ec6b66 100644
--- a/docs/PERFORMANCE.md
+++ b/docs/PERFORMANCE.md
@@ -182,6 +182,32 @@ beat are the ones in the table above and the first thing to do with that fixture
 `openAFolderOfAThousandFiles` and look at the *min* iteration rather than the median — the minimum is what
 "first rows visible" now governs.
 
+### Measured: the batched read
+
+The fixture was rebuilt and the same benchmark run against it, on the same phone, with only the listing
+changed:
+
+| 20 000 files, `openAFolderOfAThousandFiles` | one batch | 200-entry batches |
+|---|---|---|
+| min | 166 frames | **10** |
+| median | 184 frames | **12** |
+| max | 598 frames | **48** |
+
+**Ten to twelve frames is about 0.17–0.20 s** — inside the range where an interaction reads as instant —
+against roughly three seconds before, and the outlier fell from 598 to 48. The change is a factor of
+fifteen on the median and it costs nothing: the same reads happen, the same `stat`s, they are simply
+delivered as they complete instead of after the last one.
+
+What that number is *not*: the time to *use* the whole folder. The first batch is what the test's wait sees
+(`file-0.txt` is inside it), so these frames measure "first rows on screen". The remaining nineteen-odd
+batches still take the ~2 s described above — they arrive behind the progress bar, into a list the user is
+already scrolling rather than into an empty screen. Both halves matter, and only the first one is in this
+table.
+
+And the fixture now survives: `tools/benchmark-fixture.sh --count 20000` reuses a folder that already holds
+at least that many files, and `--fresh` rebuilds it. Building it takes about half an hour through MIUI's
+storage layer, which is the whole reason to keep it.
+
 Building that fixture is the expensive part, not measuring it: 20 000 files took about thirty minutes
 through MIUI's storage layer (`: >` in a loop), against roughly four minutes of benchmark on top. Worth
 knowing before anyone re-creates it, and an argument for the fixture being built once and kept.