diff --git a/docs/guides/cast-to-a-tv.md b/docs/guides/cast-to-a-tv.md
index 0c67db99..3191a91f 100644
--- a/docs/guides/cast-to-a-tv.md
+++ b/docs/guides/cast-to-a-tv.md
@@ -94,9 +94,10 @@ can use the TV as a display, read its remote, speak through it and play video
 on it.
 
 - **The TV as a display.** `RokuDisplay` is a framebuffer display whose frames
-  show full-screen, sent as PNGs. At 480x270 a desktop gets 6 to 10 frames a
-  second onto the TV, and a P4 about 2. The TV fetching each PNG sets that
-  limit: the program itself draws at 28 to 29.
+  show full-screen, sent as PNGs. At 480x270 a desktop gets 8 to 14 frames a
+  second onto the TV, and a P4 about 2. On a desktop the TV fetching each PNG
+  sets that limit, and the program itself draws at 28 to 29. On a P4 it's the
+  270 to 290 ms each PNG takes to encode.
 - **The remote as input.** All eleven buttons a channel can see arrive as key
   presses and releases, and a held button repeats. testris plays from the
   couch through [`roku/board_config.py`](https://github.com/PyDevices/pydevices-examples/blob/main/lib/examples/roku/board_config.py).
diff --git a/docs/reference/cast-runtimes.md b/docs/reference/cast-runtimes.md
index 479ff5ac..3cd96d35 100644
--- a/docs/reference/cast-runtimes.md
+++ b/docs/reference/cast-runtimes.md
@@ -6,13 +6,17 @@ for testris and for the LVGL `lv_test_timer`.
 
 | Runtime | Companion channel | Miracast to a Roku | Miracast to Windows | HLS |
 |---|---|---|---|---|
-| `python` (Linux) | 8.2, 9.1 | 30, 30 | 30 | plays |
-| `python.exe` (Windows) | 12.2, 10.6 | 30, 30 | 30 | plays |
-| `micropython` (unix) | 11.8, 7.4 | no H.264 | no H.264 | no H.264 |
-| `micropython.exe` (Windows) | 8.4, 7.7 | no H.264 | no H.264 | no H.264 |
-| ESP32-P4 4" panel | 2.2, 2.1 | 29, 18 | 30 | plays |
+| `python` (Linux) | 11.0, 9.1 | 30, 30 | 30 | plays |
+| `python.exe` (Windows) | [closes](https://github.com/PyDevices/pydevices-examples/issues/245), 13.6 | 30, 30 | 30 | plays |
+| `micropython` (unix) | 13.4, 11.3 | no H.264 | no H.264 | no H.264 |
+| `micropython.exe` (Windows) | 7.7, 7.8 | no H.264 | no H.264 | no H.264 |
+| ESP32-P4 4" panel | 2.2, 2.1 | -, 29 | 30 | plays |
 | ESP32-S3 LCD-7 | 1.8, 1.7 | no H.264 | no H.264 | no H.264 |
 
+A dash is a figure we haven't measured. On Windows CPython, testris over the
+Companion channel closes the cast a moment after it starts
+([#245](https://github.com/PyDevices/pydevices-examples/issues/245)).
+
 **No H.264** is by design. Desktop MicroPython and the S3 have no H.264
 encoder, and adding one isn't planned, so `CastDisplay` and `HlsDisplay` stop
 there with an error that says so. On CPython, ffmpeg does the encoding: put it
@@ -25,6 +29,6 @@ the same MPEG-TS over RTP that the P4 sends, byte for byte.
 it needs a second PC as the receiver: Windows won't take a cast from itself.
 
 On a desktop, a frame costs a few milliseconds of PNG encoding. On the P4 it's
-about 180 ms at 480x270 and on the S3 about 380 ms, which is why the boards get
-2 frames a second over the Companion channel and 18 to 29 over Miracast, where the P4's H.264 encoder
-does the work.
+about 270 to 290 ms at 480x270 and on the S3 about 380 ms, which is why the
+boards get 2 frames a second over the Companion channel and about 29 over
+Miracast, where the P4's H.264 encoder does the work.