diff --git a/docs/ARCHITECTURE.md b/docs/ARCHITECTURE.md
index 97c58bf..e5d0041 100644
--- a/docs/ARCHITECTURE.md
+++ b/docs/ARCHITECTURE.md
@@ -352,7 +352,7 @@ rewriting the document.
 | 1 | Separate services over a message bus, not one process | Accepted | 2026-08-14 |
 | 2 | Displays are bus subscribers; no display-specific logic upstream | Accepted | 2026-08-14 |
 | 3 | Listen-only sniffing + active OBD-II, single writer | Accepted | 2026-08-14 |
-| 4 | MQTT as the bus (raw CAN rate still to confirm) | Accepted | 2026-10-12 |
+| 4 | MQTT as the bus; raw CAN rate confirmed on the car Orin (svc-core `BUS-BENCH.md`) | Accepted | 2026-10-12 |
 | 5 | Rust for on-Orin services, Python for off-car tooling, Dart for the display client. One exception: decision 29 | Accepted | 2026-09-04 |
 | 21 | Two clocks per envelope; `monotonic` orders, `timestamp` references | Accepted | 2026-09-05 |
 | 22 | `signals.json` is the single source for signal name and unit; both are derived, never authored twice | Accepted | 2026-09-05 |
diff --git a/docs/ROADMAP.md b/docs/ROADMAP.md
index c011ff2..ded81a8 100644
--- a/docs/ROADMAP.md
+++ b/docs/ROADMAP.md
@@ -70,7 +70,9 @@ provides a cross-check for reverse-engineered ones.
 - [x] Stand up the broker, 2026-10-12: mosquitto 2.0.11 on the car Orin,
       localhost only. First publisher `orin-status` (svc-core,
       `yukart/host/*`); `svc-gw` subscribes and serves it to the tablet
-- [ ] Confirm MQTT holds up at real CAN rates (`yukart/can/raw`)
+- [x] Confirm MQTT holds up at real CAN rates (`yukart/can/raw`), 2026-10-12:
+      no loss at a saturated bus, per frame or in 10 ms batches; batched costs
+      the broker ~1 % of a core (svc-core `BUS-BENCH.md`)
 - [ ] Freeze v1 of topic names and payload schemas
 - [ ] `telemetry-gw` — external client access, including the serial bridge