diff --git a/src-tauri/Cargo.lock b/src-tauri/Cargo.lock
index add173e..02de222 100644
--- a/src-tauri/Cargo.lock
+++ b/src-tauri/Cargo.lock
@@ -141,6 +141,7 @@ dependencies = [
  "serde_with",
  "tauri",
  "tauri-build",
+ "tokio",
  "windows 0.52.0",
  "windows-version",
 ]
diff --git a/src-tauri/Cargo.toml b/src-tauri/Cargo.toml
index e0ca2c1..fff9b5f 100644
--- a/src-tauri/Cargo.toml
+++ b/src-tauri/Cargo.toml
@@ -12,6 +12,7 @@ raw-window-handle = "0.5"
 serde = { version = "1.0", features = ["derive"] }
 serde_with = { version = "3.0", features = ["base64"] }
 tauri = { version = "1.5.x", features = ["wry", "window-set-focus", "window-set-position", "window-set-size", "window-show", "window-hide", "system-tray"], default-features = false }
+tokio = { version = "1.0", features = ["time"] }
 windows-version = "0.1"
 
 [dependencies.windows]
diff --git a/src-tauri/src/monitors.rs b/src-tauri/src/monitors.rs
index e378e25..97d1655 100644
--- a/src-tauri/src/monitors.rs
+++ b/src-tauri/src/monitors.rs
@@ -2,13 +2,14 @@ use std::ffi::OsStr;
 
 use monitor::{Feature, Interface, Monitor};
 use serde::{Deserialize, Serialize};
-use tauri::async_runtime::RwLock;
+use tauri::async_runtime::{Mutex, RwLock};
 use tauri::State;
+use tokio::time::{sleep, sleep_until, Duration, Instant};
 
 use crate::util::JSResult;
 
 #[derive(Debug)]
-pub struct Monitors(RwLock<Vec<Monitor>>);
+pub struct Monitors(RwLock<Vec<(Monitor, Mutex<Instant>)>>);
 
 impl Monitors {
     pub const fn new() -> Monitors {
@@ -20,8 +21,9 @@ impl Monitors {
 pub async fn refresh_monitors(monitors: State<'_, Monitors>) -> JSResult<()> {
     let mut monitors = monitors.0.write().await;
     monitors.clear();
+    let stub_instant = Instant::now();
     for monitor in monitor::get_monitors() {
-        monitors.push(monitor);
+        monitors.push((monitor, Mutex::const_new(stub_instant)));
     }
     Ok(())
 }
@@ -31,15 +33,18 @@ pub async fn get_monitors(monitors: State<'_, Monitors>) -> JSResult<Vec<String>
     let monitors = monitors.0.read().await;
     Ok(monitors
         .iter()
-        .map(|monitor| monitor.id.to_string_lossy().into_owned())
+        .map(|(monitor, _)| monitor.id.to_string_lossy().into_owned())
         .collect())
 }
 
-fn get_monitor_by_id<'a>(monitors: &'a [Monitor], id: &'_ str) -> JSResult<&'a Monitor> {
+fn get_monitor_by_id<'a>(
+    monitors: &'a [(Monitor, Mutex<Instant>)],
+    id: &'_ str,
+) -> JSResult<&'a (Monitor, Mutex<Instant>)> {
     let id_os: &OsStr = id.as_ref();
     monitors
         .iter()
-        .find(|monitor| monitor.id == id_os)
+        .find(|(monitor, _)| monitor.id == id_os)
         .ok_or_else(|| format!("no such monitor: '{id}'").into())
 }
 
@@ -49,7 +54,7 @@ pub async fn get_monitor_user_friendly_name(
     id: String,
 ) -> JSResult<Option<String>> {
     let monitors = monitors.0.read().await;
-    let monitor = get_monitor_by_id(&monitors, &id)?;
+    let monitor = &get_monitor_by_id(&monitors, &id)?.0;
     Ok(monitor
         .get_user_friendly_name()?
         .map(|s| s.to_string_lossy().into_owned()))
@@ -74,6 +79,9 @@ pub struct Reply {
     source: &'static str,
 }
 
+// TODO: move it into JS
+const UPDATE_INTERVAL: Duration = Duration::from_millis(200);
+
 #[tauri::command]
 pub async fn get_monitor_feature(
     monitors: State<'_, Monitors>,
@@ -81,13 +89,18 @@ pub async fn get_monitor_feature(
     feature: String,
 ) -> JSResult<Reply> {
     let monitors = monitors.0.read().await;
-    let monitor = get_monitor_by_id(&monitors, &id)?;
+    let (monitor, instant) = get_monitor_by_id(&monitors, &id)?;
     let feature = feature_from_string(feature)?;
+
+    let mut instant = instant.lock().await;
+    sleep_until(*instant).await;
     let monitor::Reply {
         current,
         maximum,
         source,
     } = monitor.get_feature(feature)?;
+    *instant = Instant::now() + UPDATE_INTERVAL;
+
     Ok(Reply {
         current,
         maximum,
@@ -104,9 +117,29 @@ pub async fn set_monitor_feature(
     id: String,
     feature: String,
     value: u32,
-) -> JSResult<()> {
+) -> JSResult<Reply> {
     let monitors = monitors.0.read().await;
-    let monitor = get_monitor_by_id(&monitors, &id)?;
+    let (monitor, instant) = get_monitor_by_id(&monitors, &id)?;
     let feature = feature_from_string(feature)?;
-    Ok(monitor.set_feature(feature, value)?)
+
+    let mut instant = instant.lock().await;
+    sleep_until(*instant).await;
+    monitor.set_feature(feature, value)?;
+
+    sleep(UPDATE_INTERVAL).await;
+    let monitor::Reply {
+        current,
+        maximum,
+        source,
+    } = monitor.get_feature(feature)?;
+    *instant = Instant::now() + UPDATE_INTERVAL;
+
+    Ok(Reply {
+        current,
+        maximum,
+        source: match source {
+            Interface::DDCCI => "ddcci",
+            Interface::IOCTL => "ioctl",
+        },
+    })
 }
diff --git a/src/components/FeatureSlider.vue b/src/components/FeatureSlider.vue
index eeb0a5c..f3f713b 100644
--- a/src/components/FeatureSlider.vue
+++ b/src/components/FeatureSlider.vue
@@ -1,9 +1,8 @@
 <script lang="ts">
 import { defineComponent } from "vue";
-import { clamp, debounce } from "lodash-es";
+import { clamp } from "lodash-es";
 import monitorManager from "../monitor";
 import sheet from "../style.module.sass";
-import settings from "../settings";
 
 const iconMap: { [key: string]: string } = {
     luminance: "\uE706",
@@ -31,9 +30,11 @@ export default defineComponent({
     },
     data(): {
         input: number | null;
+        updating: Promise<void>;
     } {
         return {
             input: null,
+            updating: Promise.resolve(),
         };
     },
     computed: {
@@ -49,25 +50,6 @@ export default defineComponent({
         icon() {
             return iconMap[this.featureName];
         },
-        update() {
-            const { updateInterval } = settings;
-            return debounce(
-                (id, name, value) => {
-                    monitorManager.setFeature(id, name, value);
-                },
-                updateInterval,
-                {
-                    leading: true,
-                    maxWait: updateInterval,
-                },
-            );
-        },
-        sync() {
-            const { updateInterval } = settings;
-            return debounce(() => {
-                this.input = null;
-            }, updateInterval * 2);
-        },
     },
     methods: {
         handleInput(event: Event) {
@@ -75,7 +57,7 @@ export default defineComponent({
             const target = e.target! as HTMLInputElement;
             if (!e.isComposing && target.validity.valid) {
                 this.input = Number(target.value);
-                this.update(this.monitorId, this.featureName, this.input);
+                this.update();
             }
         },
         handleWheel(event: Event) {
@@ -85,10 +67,30 @@ export default defineComponent({
                 const offset = Math.abs(e.deltaX) > Math.abs(e.deltaY) ? e.deltaX : -e.deltaY;
                 const current = Number(target.value);
                 this.input = clamp(Math.round(current + offset * 0.01), 0, this.maximum);
-                this.update(this.monitorId, this.featureName, this.input);
+                this.update();
                 this.sync();
             }
         },
+        update() {
+            this.updating = this.updating.then(() => {
+                if (this.input != null) {
+                    try {
+                        return monitorManager.setFeature(
+                            this.monitorId,
+                            this.featureName,
+                            this.input,
+                        );
+                    } catch (e) {
+                        console.error(e);
+                    }
+                }
+            });
+        },
+        sync() {
+            this.updating = this.updating.then(() => {
+                this.input = null;
+            });
+        },
     },
 });
 </script>
diff --git a/src/monitor.ts b/src/monitor.ts
index 97f6698..15f0ed0 100644
--- a/src/monitor.ts
+++ b/src/monitor.ts
@@ -1,6 +1,5 @@
 import { invoke } from "@tauri-apps/api";
 import { reactive, toRaw, DeepReadonly } from "vue";
-import settings from "./settings";
 
 export interface Reply {
     current: number;
@@ -19,12 +18,6 @@ export interface Monitor {
     features: Feature[];
 }
 
-function timeout(millis: number): Promise<undefined> {
-    return new Promise((resolve) => {
-        setTimeout(resolve, millis);
-    });
-}
-
 export class Manager {
     readonly monitors: DeepReadonly<Monitor[]> = reactive([]);
     private refreshing = false;
@@ -66,11 +59,7 @@ export class Manager {
                     const featureNames = monitor.features.length
                         ? monitor.features.map((feature) => feature.name)
                         : ["luminance", "contrast", "brightness", "volume", "powerstate"];
-                    let first = true;
                     for (const name of featureNames) {
-                        if (!first) {
-                            await timeout(settings.updateInterval);
-                        }
                         let value: Reply | undefined;
                         try {
                             value = await invoke<Reply>("get_monitor_feature", {
@@ -92,7 +81,6 @@ export class Manager {
                         } else if (idx != -1) {
                             monitor.features.splice(idx, 1);
                         }
-                        first = false;
                     }
                 })(),
             );
@@ -131,17 +119,12 @@ export class Manager {
     async setFeature(id: string, name: string, value: number): Promise<void> {
         const feature = this.getFeature(id, name) as Feature;
         if (feature.value.current != value) {
-            await invoke<void>("set_monitor_feature", {
-                id,
-                feature: name,
-                value,
-            });
-            await timeout(settings.updateInterval);
             Object.assign(
                 feature.value,
-                await invoke<Reply>("get_monitor_feature", {
+                await invoke<Reply>("set_monitor_feature", {
                     id,
                     feature: name,
+                    value,
                 }),
             );
         }