diff --git a/changelog.d/18510.misc b/changelog.d/18510.misc
new file mode 100644
index 0000000000..71a3549d31
--- /dev/null
+++ b/changelog.d/18510.misc
@@ -0,0 +1 @@
+Distinguish all vs local events being persisted in the "Event Send Time Quantiles" graph (Grafana).
diff --git a/contrib/grafana/synapse.json b/contrib/grafana/synapse.json
index 30d6d87500..62b58a199d 100644
--- a/contrib/grafana/synapse.json
+++ b/contrib/grafana/synapse.json
@@ -220,29 +220,24 @@
       "yBucketBound": "auto"
     },
     {
-      "aliasColors": {},
-      "bars": false,
-      "dashLength": 10,
-      "dashes": false,
       "datasource": {
-        "uid": "${DS_PROMETHEUS}"
+        "uid": "${DS_PROMETHEUS}",
+        "type": "prometheus"
       },
-      "description": "",
+      "aliasColors": {},
+      "dashLength": 10,
       "fieldConfig": {
         "defaults": {
           "links": []
         },
         "overrides": []
       },
-      "fill": 0,
-      "fillGradient": 0,
       "gridPos": {
         "h": 9,
         "w": 12,
         "x": 12,
         "y": 1
       },
-      "hiddenSeries": false,
       "id": 152,
       "legend": {
         "avg": false,
@@ -255,71 +250,81 @@
         "values": false
       },
       "lines": true,
-      "linewidth": 0,
-      "links": [],
       "nullPointMode": "connected",
       "options": {
         "alertThreshold": true
       },
       "paceLength": 10,
-      "percentage": false,
-      "pluginVersion": "9.2.2",
+      "pluginVersion": "10.4.3",
       "pointradius": 5,
-      "points": false,
       "renderer": "flot",
       "seriesOverrides": [
         {
           "alias": "Avg",
           "fill": 0,
-          "linewidth": 3
+          "linewidth": 3,
+          "$$hashKey": "object:48"
         },
         {
           "alias": "99%",
           "color": "#C4162A",
-          "fillBelowTo": "90%"
+          "fillBelowTo": "90%",
+          "$$hashKey": "object:49"
         },
         {
           "alias": "90%",
           "color": "#FF7383",
-          "fillBelowTo": "75%"
+          "fillBelowTo": "75%",
+          "$$hashKey": "object:50"
         },
         {
           "alias": "75%",
           "color": "#FFEE52",
-          "fillBelowTo": "50%"
+          "fillBelowTo": "50%",
+          "$$hashKey": "object:51"
         },
         {
           "alias": "50%",
           "color": "#73BF69",
-          "fillBelowTo": "25%"
+          "fillBelowTo": "25%",
+          "$$hashKey": "object:52"
         },
         {
           "alias": "25%",
           "color": "#1F60C4",
-          "fillBelowTo": "5%"
+          "fillBelowTo": "5%",
+          "$$hashKey": "object:53"
         },
         {
           "alias": "5%",
-          "lines": false
+          "lines": false,
+          "$$hashKey": "object:54"
         },
         {
           "alias": "Average",
           "color": "rgb(255, 255, 255)",
           "lines": true,
-          "linewidth": 3
+          "linewidth": 3,
+          "$$hashKey": "object:55"
         },
         {
-          "alias": "Events",
+          "alias": "Local events being persisted",
+          "color": "#96d98D",
+          "points": true,
+          "yaxis": 2,
+          "zindex": -3,
+          "$$hashKey": "object:56"
+        },
+        {
+          "$$hashKey": "object:329",
           "color": "#B877D9",
-          "hideTooltip": true,
+          "alias": "All events being persisted",
           "points": true,
           "yaxis": 2,
           "zindex": -3
         }
       ],
       "spaceLength": 10,
-      "stack": false,
-      "steppedLine": false,
       "targets": [
         {
           "datasource": {
@@ -384,7 +389,20 @@
           },
           "expr": "sum(rate(synapse_http_server_response_time_seconds_sum{servlet='RoomSendEventRestServlet',index=~\"$index\",instance=\"$instance\",code=~\"2..\"}[$bucket_size])) / sum(rate(synapse_http_server_response_time_seconds_count{servlet='RoomSendEventRestServlet',index=~\"$index\",instance=\"$instance\",code=~\"2..\"}[$bucket_size]))",
           "legendFormat": "Average",
-          "refId": "H"
+          "refId": "H",
+          "editorMode": "code",
+          "range": true
+        },
+        {
+          "datasource": {
+            "uid": "${DS_PROMETHEUS}"
+          },
+          "expr": "sum(rate(synapse_http_server_response_time_seconds_count{servlet='RoomSendEventRestServlet',index=~\"$index\",instance=\"$instance\",code=~\"2..\"}[$bucket_size]))",
+          "hide": false,
+          "instant": false,
+          "legendFormat": "Local events being persisted",
+          "refId": "E",
+          "editorMode": "code"
         },
         {
           "datasource": {
@@ -393,8 +411,9 @@
           "expr": "sum(rate(synapse_storage_events_persisted_events_total{instance=\"$instance\"}[$bucket_size]))",
           "hide": false,
           "instant": false,
-          "legendFormat": "Events",
-          "refId": "E"
+          "legendFormat": "All events being persisted",
+          "refId": "I",
+          "editorMode": "code"
         }
       ],
       "thresholds": [
@@ -428,7 +447,9 @@
       "xaxis": {
         "mode": "time",
         "show": true,
-        "values": []
+        "values": [],
+        "name": null,
+        "buckets": null
       },
       "yaxes": [
         {
@@ -450,7 +471,20 @@
       ],
       "yaxis": {
         "align": false
-      }
+      },
+      "bars": false,
+      "dashes": false,
+      "description": "",
+      "fill": 0,
+      "fillGradient": 0,
+      "hiddenSeries": false,
+      "linewidth": 0,
+      "percentage": false,
+      "points": false,
+      "stack": false,
+      "steppedLine": false,
+      "timeFrom": null,
+      "timeShift": null
     },
     {
       "aliasColors": {},