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Performance regression with Impeller rendering compared to Skia backend #169423

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Performance regression with Impeller rendering compared to Skia backend#169423
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P2Important issues not at the top of the work listc: performanceRelates to speed or footprint issues (see "perf:" labels)e: impellerImpeller rendering backend issues and features requestsengineflutter/engine related. See also e: labels.found in release: 3.32Found to occur in 3.32found in release: 3.33Found to occur in 3.33has reproducible stepsThe issue has been confirmed reproducible and is ready to work onperf: speedPerformance issues related to (mostly rendering) speedplatform-androidAndroid applications specificallyteam-engineOwned by Engine teamtriaged-engineTriaged by Engine team

Description

@mixedteam236
mixedteam236
opened on May 24, 2025

Steps to reproduce

  1. Clone the repro project:

    git clone https://github.com/mixedteam236/impeller_test.git
cd impeller_test

  2. Ensure to be on Flutter 3.32.0 (stable) or newer:

    flutter --version

  3. Run the app with Impeller enabled (release mode):

    flutter run --release

  4. Observe the animation performance after tapping the button at bottom right.

  5. Stop the app, then run with Impeller disabled (Skia default):

    flutter run --release --no-enable-impeller

  6. Compare the smoothness and reported FPS between both runs.

Expected behavior
With Impeller enabled, animations should be as smooth as (or smoother than) the Skia backend, maintaining a steady 60 FPS on supported devices in release mode.

Actual behavior
Impeller enabled: Frame rate drops significantly, with noticeable stuttering and frame skips.

Impeller disabled (Skia): Consistent 60 FPS, smooth animations across the board.

Code sample

Code sample

See GitHub repository: https://github.com/mixedteam236/impeller_test.git

Performance profiling on master channel

  • The issue still persists on the master channel

Timeline Traces

dart_devtools_2025-05-25_00_57_25.809.zip

Video demonstration

Video demonstration
impeller_enabled_recorded_with_camera impeller_not_enabled_recorded_with_camera
impeller_enabled_recorded_with_camera.mp4
impeller_not_enabled_recorded_with_camera.mp4
impeller_enabled impeller_not_enabled
impeller_enabled.mp4
impeller_not_enabled.mp4

What target platforms are you seeing this bug on?

Android

OS/Browser name and version | Device information

Operating System: Android 15

Model: ASUS Zenfone 10 (AI2302)

SoC: Qualcomm Snapdragon 8 Gen 2 (SM8550-AB, 4 nm)

CPU: Octa-core (1×3.2 GHz Cortex-X3 + 2×2.8 GHz Cortex-A715 + 2×2.8 GHz Cortex-A710 + 3×2.0 GHz Cortex-A510)

GPU: Adreno 740

Memory (RAM): 8 GB LPDDR5X

ABI / Architecture: arm64-v8a (64-bit)

Does the problem occur on emulator/simulator as well as on physical devices?

Unknown

Is the problem only reproducible with Impeller?

Yes

Logs

Logs

impeller_test_log.txt

Flutter Doctor output

Doctor output 
[√] Flutter (Channel stable, 3.32.0, on Microsoft Windows [Version 10.0.26100.4061], locale de-DE) [638ms]
    • Flutter version 3.32.0 on channel stable at c:\Progs\flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision be698c48a6 (5 days ago), 2025-05-19 12:59:14 -0700
    • Engine revision 1881800949
    • Dart version 3.8.0
    • DevTools version 2.45.1

[√] Windows Version (11 Home 64-bit, 24H2, 2009) [2,9s]

[√] Android toolchain - develop for Android devices (Android SDK version 35.0.0) [3,1s]
    • Android SDK at c:\Progs\AndroidSdk
    • Platform android-36, build-tools 35.0.0
    • ANDROID_HOME = c:\Progs\AndroidSdk
    • Java binary at: C:\Users\Me\AppData\Local\Programs\Android Studio\jbr\bin\java
      This is the JDK bundled with the latest Android Studio installation on this machine.
      To manually set the JDK path, use: `flutter config --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment (build 21.0.6+-13368085-b895.109)
    • All Android licenses accepted.

[√] Chrome - develop for the web [337ms]
    • Chrome at C:\Program Files (x86)\Google\Chrome\Application\chrome.exe

[X] Visual Studio - develop Windows apps [335ms]
    X Visual Studio not installed; this is necessary to develop Windows apps.
      Download at https://visualstudio.microsoft.com/downloads/.
      Please install the "Desktop development with C++" workload, including all of its default components

[√] Android Studio (version 2024.3.2) [96ms]
    • Android Studio at C:\Users\Me\AppData\Local\Programs\Android Studio
    • Flutter plugin can be installed from:
       https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
       https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 21.0.6+-13368085-b895.109)

[√] IntelliJ IDEA Community Edition (version 2024.2) [94ms]
    • IntelliJ at D:\Progs\IntelliJ
    • Flutter plugin can be installed from:
       https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin version 242.26775.15

[√] IntelliJ IDEA Community Edition (version 2025.1) [51ms]
    • IntelliJ at C:\Users\Me\AppData\Local\Programs\IntelliJ IDEA Community Edition
    • Flutter plugin can be installed from:
       https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin version 251.25410.28

[√] Connected device (4 available) [314ms]
    • ASUS AI2302 (mobile) • RCAIB700B06699H • android-arm64  • Android 15 (API 35)
    • Windows (desktop)    • windows         • windows-x64    • Microsoft Windows [Version 10.0.26100.4061]
    • Chrome (web)         • chrome          • web-javascript • Google Chrome 136.0.7103.114
    • Edge (web)           • edge            • web-javascript • Microsoft Edge 135.0.3179.54

[√] Network resources [340ms]
    • All expected network resources are available.

! Doctor found issues in 1 category.

Activity

  1. mixedteam236
    added
    from: performance templateIssues created via a performance issue template
    on May 24, 2025
  2. tirth-patel-nc
    added
    in triagePresently being triaged by the triage team
    and removed
    from: performance templateIssues created via a performance issue template
    on May 26, 2025

  3. tirth-patel-nc commented on May 26, 2025

    @tirth-patel-nc
    tirth-patel-nc
    on May 26, 2025
    Member

    Triage Report

    I was able to reproduce the issue using the provided code sample on the stable (3.29.3), stable (3.32.0) and master (3.33.0-1.0.pre.211) channels. Tested on Pixel 6a (real device with --release).

    with --no-enable-impeller it works better.

    stable (3.29.3) - flutter doctor -v 
    [✓] Flutter (Channel stable, 3.29.3, on macOS 15.4.1 24E263 darwin-arm64, locale
    en-IN) [970ms]
    • Flutter version 3.29.3 on channel stable at
      /Users/tirthpatel/Development/flutter_stable/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision ea121f8859 (4 weeks ago), 2025-04-11 19:10:07 +0000
    • Engine revision cf56914b32
    • Dart version 3.7.2
    • DevTools version 2.42.3

[✓] Android toolchain - develop for Android devices (Android SDK version 36.0.0)
    [855ms]
    • Android SDK at /Users/tirthpatel/Library/Android/sdk
    • Platform android-36, build-tools 36.0.0
    • Java binary at: /Applications/Android
      Studio.app/Contents/jbr/Contents/Home/bin/java
      This is the JDK bundled with the latest Android Studio installation on
      this machine.
      To manually set the JDK path, use: `flutter config
      --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment (build 21.0.6+-13355223-b631.42)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 16.3) [556ms]
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 16E140
    • CocoaPods version 1.16.2

[✓] Chrome - develop for the web [9ms]
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2024.3) [9ms]
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 21.0.6+-13355223-b631.42)

[✓] VS Code (version 1.99.3) [8ms]
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension can be installed from:
      🔨 https://marketplace.visualstudio.com/items?itemName=Dart-Code.flutter

[✓] Connected device (3 available) [5.5s]
    • macOS (desktop)                 • macos                 • darwin-arm64   •
      macOS 15.4.1 24E263 darwin-arm64
    • Mac Designed for iPad (desktop) • mac-designed-for-ipad • darwin         •
      macOS 15.4.1 24E263 darwin-arm64
    • Chrome (web)                    • chrome                • web-javascript •
      Google Chrome 135.0.7049.115

[✓] Network resources [559ms]
    • All expected network resources are available.

• No issues found!
    stable (3.32.0) - flutter doctor -v 
    [✓] Flutter (Channel stable, 3.32.0, on macOS 15.4.1 24E263 darwin-arm64, locale en-IN) [446ms]
    • Flutter version 3.32.0 on channel stable at /Users/tirthpatel/Development/flutter_stable_latest/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision be698c48a6 (34 hours ago), 2025-05-19 12:59:14 -0700
    • Engine revision 1881800949
    • Dart version 3.8.0
    • DevTools version 2.45.1

[✓] Android toolchain - develop for Android devices (Android SDK version 36.0.0) [827ms]
    • Android SDK at /Users/tirthpatel/Library/Android/sdk
    • Platform android-36, build-tools 36.0.0
    • Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
      This is the JDK bundled with the latest Android Studio installation on this machine.
      To manually set the JDK path, use: `flutter config --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment (build 21.0.6+-13355223-b631.42)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 16.3) [448ms]
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 16E140
    • CocoaPods version 1.16.2

[✓] Chrome - develop for the web [9ms]
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2024.3) [8ms]
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 21.0.6+-13355223-b631.42)

[✓] VS Code (version 1.100.2) [8ms]
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.110.0

[✓] Connected device (2 available) [5.6s]
    • macOS (desktop) • macos  • darwin-arm64   • macOS 15.4.1 24E263 darwin-arm64
    • Chrome (web)    • chrome • web-javascript • Google Chrome 136.0.7103.114

[✓] Network resources [1,624ms]
    • All expected network resources are available.

• No issues found!
    master (3.33.0-1.0.pre.211) - flutter doctor -v 
    [✓] Flutter (Channel master, 3.33.0-1.0.pre.211, on macOS 15.4.1 24E263 darwin-arm64, locale en-IN) [2.9s]
    • Flutter version 3.33.0-1.0.pre.211 on channel master at /Users/tirthpatel/Development/flutter_master/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 1430fc8e8d (28 hours ago), 2025-05-24 23:59:26 -0400
    • Engine revision 1430fc8e8d
    • Dart version 3.9.0 (build 3.9.0-169.0.dev)
    • DevTools version 2.46.0

[✓] Android toolchain - develop for Android devices (Android SDK version 36.0.0) [4.5s]
    • Android SDK at /Users/tirthpatel/Library/Android/sdk
    • Emulator version 35.4.9.0 (build_id 13025442) (CL:N/A)
    • Platform android-36, build-tools 36.0.0
    • Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
      This is the JDK bundled with the latest Android Studio installation on this machine.
      To manually set the JDK path, use: `flutter config --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment (build 21.0.6+-13355223-b631.42)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 16.3) [814ms]
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 16E140
    • CocoaPods version 1.16.2

[✓] Chrome - develop for the web [8ms]
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2024.3) [8ms]
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 21.0.6+-13355223-b631.42)

[✓] VS Code (version 1.100.2) [7ms]
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.110.0

[✓] Connected device (4 available) [5.7s]
    • sdk gphone64 arm64 (mobile) • emulator-5554                        • android-arm64  • Android 16 (API 36) (emulator)
    • iPhone 16 Plus (mobile)     • B19185FD-0093-4E49-B587-16642A3EC7D3 • ios            • com.apple.CoreSimulator.SimRuntime.iOS-18-4 (simulator)
    • macOS (desktop)             • macos                                • darwin-arm64   • macOS 15.4.1 24E263 darwin-arm64
    • Chrome (web)                • chrome                               • web-javascript • Google Chrome 136.0.7103.114

[✓] Network resources [430ms]
    • All expected network resources are available.

• No issues found!
  4. tirth-patel-nc
    added
    engineflutter/engine related. See also e: labels.
    e: impellerImpeller rendering backend issues and features requests
    team-engineOwned by Engine team
    c: performanceRelates to speed or footprint issues (see "perf:" labels)
    perf: speedPerformance issues related to (mostly rendering) speed
    platform-androidAndroid applications specifically
    has reproducible stepsThe issue has been confirmed reproducible and is ready to work on
    found in release: 3.32Found to occur in 3.32
    found in release: 3.33Found to occur in 3.33
    and removed
    in triagePresently being triaged by the triage team
    on May 26, 2025

  5. jonahwilliams commented on May 30, 2025

    @jonahwilliams
    jonahwilliams
    on May 30, 2025
    Contributor

    The performance problem we're running into here has to do with non-symmetrical rrect blurs. We can't use the fast path approach and so we fall back to a generic gaussian. I think this will keep coming up. For blurs of generic geometry masks we need a faster approach.

  6. jonahwilliams
    added
    P2Important issues not at the top of the work list
    triaged-engineTriaged by Engine team
    on Jun 2, 2025

  7. Zabadam commented on Nov 13, 2025

    @Zabadam
    Zabadam
    on Nov 13, 2025
    Contributor

    I have been revising a demo app for a package I was writing that involved a lot of color math and palette generation. While the demo could be improved logically for better performance, it behaves smoothly [enough] on Windows and Android with --no-enable-impellerbut chugs down to a slideshow with Impeller enabled.

    I am not using any explicit clip rects, so I don't think my performance degradation is directly related to this one; but the title of the issue matches my problem.

    Should I form a new issue for my case?

    Left: Skia | Right: Impeller

    20251113_120035_1.mp4

  8. tirth-patel-nc commented on Nov 14, 2025

    @tirth-patel-nc
    tirth-patel-nc
    on Nov 14, 2025
    Member

    @Zabadam you may file a fresh issue.

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    P2Important issues not at the top of the work listc: performanceRelates to speed or footprint issues (see "perf:" labels)e: impellerImpeller rendering backend issues and features requestsengineflutter/engine related. See also e: labels.found in release: 3.32Found to occur in 3.32found in release: 3.33Found to occur in 3.33has reproducible stepsThe issue has been confirmed reproducible and is ready to work onperf: speedPerformance issues related to (mostly rendering) speedplatform-androidAndroid applications specificallyteam-engineOwned by Engine teamtriaged-engineTriaged by Engine team

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