diff --git a/.changes/dashboard-live-progress-compositor.md b/.changes/dashboard-live-progress-compositor.md
new file mode 100644
index 000000000..30d85bd9e
--- /dev/null
+++ b/.changes/dashboard-live-progress-compositor.md
@@ -0,0 +1,8 @@
+---
+type: perf
+area: dashboard
+---
+
+Live programme progress bars on the dashboard now advance without redrawing
+the whole page, so a dashboard left open with recent live channels uses less
+CPU and GPU.
diff --git a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-hero.component.html b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-hero.component.html
index 49f632790..3336ca5f3 100644
--- a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-hero.component.html
+++ b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-hero.component.html
@@ -141,7 +141,7 @@
                         aria-valuemax="100"
                         [attr.aria-valuenow]="slide.progress"
                     >
-                        <i [style.width.%]="slide.progress"></i>
+                        <i [style.--hero-progress]="slide.progress"></i>
                     </span>
                 }
 
diff --git a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-hero.component.scss b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-hero.component.scss
index 408d15802..42055bebd 100644
--- a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-hero.component.scss
+++ b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-hero.component.scss
@@ -339,10 +339,15 @@
 
     i {
         display: block;
+        width: 100%;
         height: 100%;
         border-radius: inherit;
         background: var(--app-selection-color, #78adff);
-        transition: width 0.4s ease;
+        // A full-width fill slid into place, neither a width nor animated: a
+        // live-EPG tick moves it by under one percent, so an animation was
+        // invisible yet cost a layout pass (width) or a burst of compositor
+        // frames (transform transition) on every tick.
+        transform: translateX(calc(var(--hero-progress, 0) * 1% - 100%));
     }
 
     &--live i {
diff --git a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-rail.component.html b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-rail.component.html
index 2dff0ea0d..649460d5b 100644
--- a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-rail.component.html
+++ b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-rail.component.html
@@ -126,7 +126,7 @@
                                     "
                                 >
                                     <i
-                                        [style.width.%]="
+                                        [style.--live-progress]="
                                             card.nowPlayingProgress ?? 0
                                         "
                                     ></i>
diff --git a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-rail.component.scss b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-rail.component.scss
index 485e34ced..ffc9af8d1 100644
--- a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-rail.component.scss
+++ b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-rail.component.scss
@@ -727,10 +727,19 @@
 
     i {
         display: block;
+        width: 100%;
         height: 100%;
         background: var(--app-live-color, #ff8f8f);
         border-radius: 2px;
-        transition: width 0.4s ease;
+        // A full-width fill slid into view, not an animated width: the
+        // transform transition runs on the compositor, so each live-EPG tick
+        // no longer re-lays out the whole page for every transition frame.
+        transform: translateX(calc(var(--live-progress, 0) * 1% - 100%));
+        transition: transform 0.4s ease;
+
+        @media (prefers-reduced-motion: reduce) {
+            transition: none;
+        }
     }
 
     &--idle i {
diff --git a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-rail.component.spec.ts b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-rail.component.spec.ts
index f5f748fdb..25c89a37b 100644
--- a/libs/workspace/dashboard/feature/src/lib/rails/dashboard-rail.component.spec.ts
+++ b/libs/workspace/dashboard/feature/src/lib/rails/dashboard-rail.component.spec.ts
@@ -335,6 +335,26 @@ describe('DashboardRailComponent', () => {
             expect(visible.at(-1)).toEqual(['a', 'b']);
         });
 
+        it('positions the live progress fill through a custom property, never its width', async () => {
+            // Animating width re-lays out the page for every frame of the
+            // transition on each EPG tick; the stylesheet slides the fill with
+            // a compositor transform driven by this property instead.
+            installObservers(false);
+            const { fixture } = await render([
+                card({ id: 'known', contentType: 'live', nowPlayingProgress: 37.5 }),
+                card({ id: 'unknown', contentType: 'live' }),
+            ]);
+            const fills = Array.from(
+                (fixture.nativeElement as HTMLElement).querySelectorAll<HTMLElement>(
+                    '.rail__channel-progress i'
+                )
+            );
+            expect(fills).toHaveLength(2);
+            expect(fills[0].style.getPropertyValue('--live-progress')).toBe('37.5');
+            expect(fills[1].style.getPropertyValue('--live-progress')).toBe('0');
+            expect(fills.map((fill) => fill.style.width)).toEqual(['', '']);
+        });
+
         it('shows the placeholder only while a live card is pending its first answer', async () => {
             installObservers(false);
             const { fixture } = await render([