Steps to reproduce
When running our flutter application on this kind of device iiyama TW2223AS-B2, we noticed that the app runs very slowly, and there is a lot of stutter and lag.
So, I have compiled a sample application in release mode to test on this device. I tested this app in two ways: first with Impeller enabled, and then with Impeller disabled. And indeed, when running with Impeller disabled, the app is running smoothly. But when running with Impeller enabled, then the app becomes completely unusable (very laggy; a lot of stutter when scrolling lists; dialogs and images load very slowly; low fps overall). You can check the two live video recordings below.
Note that this device is located in a remote location, so I do not have physical access to it at this time in order to debug the app myself. I can only send and run pre-compiled apps on the device, and ask the person in charge at that location to record the screen for me.
Code sample
Code sample
The code sample from the videos is here: https://github.com/adrianflutur/flutter-iiyama-device-impeller-stuttering-issue/tree/impeller-enabled
And you can switch branches between impeller-enabled and impeller-disabled to test both cases.
Video demonstration
Video demonstration
You can see both apps running live here: https://drive.google.com/drive/folders/1OpojuMWk6odge1vFk_yO9JaIH5pwGVsg
There are two videos, one for each case: impeller-enabled and impeller-disabled.
What target platforms are you seeing this bug on?
Android
OS/Browser name and version | Device information
Device: iiyama TW2223AS-B2
Full device info
Device Info 3.4.1.3
Date Created 2026-03-11 12:26:31
Device
Device Name : tw2223as-b2
Model : TW2223AS-B2
Manufacturer : rockchip
Device : rk3399_Android12
Board : rk30sdk
Hardware : rk30board
Brand : rockchip
Build Fingerprint : rockchip/rk3399_Android12/rk3399_Android12:12/SP2A.220305.012/eng.pear.20250530.091623:userdebug/release-keys
System
Android Version : 12
Version Name : Snow Cone V2
Released Date : October 04, 2021
Code Name : Android 12L
API Level : 32
Security Patch Level : 2022-03-05
Bootloader : unknown
Build Number : TW2223AS-B2-R08-V3.3-21-N01.1-H1.4-GG-20250530
Baseband : null
Java VM : 2.1.0
Kernel : 4.19.232
Language : English (en_US)
OpenGL ES : 3.2
Root Management Apps : No Apps Detected
SELinux : Permissive
Google Play Services : 26.09.31 (190400-877989800)
Vulkan : Supported (1.3)
Treble : Supported
Seamless Updates : Not Supported
CPU
SoC : rk3399_android12 (no)
no
Processor : Rockchip RK3399
CPU Architecture : 2 x 1.80 GHz
4 x 1.42 GHz
Supported ABIs : arm64-v8a, armeabi-v7a, armeabi
CPU Hardware : Rockchip RK3399 EVB IND LPDDR4 Board lvds (Android)
CPU Type : 64 Bit
CPU Governor : interactive
Cores : 6
CPU Frequency : 2 x 408 MHz - 1800 MHz
4 x 408 MHz - 1416 MHz
GPU Renderer : Mali-T860
GPU Vendor : ARM
GPU Version : OpenGL ES 3.2 v1.r18p0-01rel0.8fe07285d44e34b76128afdd6f13ee46
Battery
Health : Unknown
Level : 0%
Status : Unknown
Power Source : Battery
Technology :
Temperature : 0 °C
Voltage : 0 mV
Network
Type : Ethernet
IP Address : 192.168.1.216
Gateway : 192.168.1.1
Subnet Mask : 255.255.255.0
DNS1 : 2a02:2f04:1d9:8700::1
DNS2 : 192.168.1.1
Interface : eth0
Connectivity
Bluetooth
Bluetooth : Supported
Multiple Advertisements : Not Supported
Offloaded Filtering : Not Supported
Offloaded Scan Batching : Not Supported
Bluetooth LE (Low Energy) : Supported
LE 2M PHY (High Speed) : Not Supported
LE Coded PHY (Long Range) : Not Supported
LE Extended Advertising : Not Supported
LE Periodic Advertising : Not Supported
Wi-Fi
WiFi Standard : Unknown
WiFi Direct : Not Supported
5GHz : Supported
6GHz : Not Supported
NFC
NFC : Not Supported
Secure NFC : Not Supported
Ultra Wide Band
Ultra Wide Band : Not Supported
USB
USB Host : Supported
USB Accessory : Supported
USB Debugging : On
Display
Resolution : 1920 x 1080 Pixels (FHD)
Density : 160 dpi (MDPI)
Font Scale : 1.0
Physical Size : 6.9 inches
Refresh Rate : • 59.0 Hz
HDR : Not Supported
HDR Capabilities : None
Brightness Level : 80%
Brightness Mode : Manual
Screen Timeout : 600 Seconds
Orientation : Portrait
Memory
Random Access Memory
Total : 3836.0MB
Available : 2099.0MB
Used : 1801.0MB
Used Percentage : 45%
System Storage
Total : 0.94GB
Available : 0.00GB
Used : 0.94GB
Used Percentage : 100%
Internal Storage
Total : 22.40GB
Available : 14.27GB
Used : 8.13GB
Used Percentage : 36%
Camera
Thermal
gpu-thermal - 38.8 °C
soc-thermal - 42.2 °C
Sensors
Accelerometer sensor
Vendor : The Android Open Source Project
Type : ACCELEROMETER
Power : 0.2mA
Compass Magnetic field sensor
Vendor : The Android Open Source Project
Type : MAGNETIC FIELD
Power : 6.8mA
Light sensor
Vendor : The Android Open Source Project
Type : LIGHT
Power : 0.5mA
Gyroscope sensor
Vendor : The Android Open Source Project
Type : GYROSCOPE
Power : 6.1mA
Game Rotation Vector Sensor
Vendor : AOSP
Type : GAME ROTATION VECTOR
Power : 13.1mA
GeoMag Rotation Vector Sensor
Vendor : AOSP
Type : GEOMAGNETIC ROTATION VECTOR
Power : 13.1mA
Gravity Sensor
Vendor : AOSP
Type : GRAVITY
Power : 13.1mA
Linear Acceleration Sensor
Vendor : AOSP
Type : LINEAR ACCELERATION
Power : 13.1mA
Rotation Vector Sensor
Vendor : AOSP
Type : ROTATION VECTOR
Power : 13.1mA
Orientation Sensor
Vendor : AOSP
Type : ORIENTATION
Power : 13.1mA
Does the problem occur on emulator/simulator as well as on physical devices?
Unknown
Is the problem only reproducible with Impeller?
Yes
Logs
No response
Flutter Doctor output
Doctor output
Note that this information is from my development device, but the target device (iiyama) is not connected. As mentioned above, that device is not physically accessible to me at this time.
$ flutter doctor -v
[√] Flutter (Channel stable, 3.32.8, on Microsoft Windows [Version 10.0.22631.6199], locale en-001) [473ms]
• Flutter version 3.32.8 on channel stable at C:\Users\ady_f\fvm\versions\3.32.8
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision edada7c56e (8 months ago), 2025-07-25 14:08:03 +0000
• Engine revision ef0cd00091
• Dart version 3.8.1
• DevTools version 2.45.1
[√] Windows Version (11 Home 64-bit, 23H2, 2009) [2.6s]
[√] Android toolchain - develop for Android devices (Android SDK version 36.0.0) [5.0s]
• Android SDK at D:\Software\dev\android-sdk
• Platform android-36, build-tools 36.0.0
• Java binary at: C:\Program Files\OpenJDK\jdk-18.0.2\bin\java
This JDK is specified in your Flutter configuration.
To change the current JDK, run: `flutter config --jdk-dir="path/to/jdk"`.
• Java version OpenJDK Runtime Environment (build 18.0.2+9-61)
• All Android licenses accepted.
[√] Chrome - develop for the web [129ms]
• Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe
[√] Visual Studio - develop Windows apps (Visual Studio Community 2019 16.11.18) [128ms]
• Visual Studio at C:\Program Files (x86)\Microsoft Visual Studio\2019\Community
• Visual Studio Community 2019 version 16.11.32802.440
• Windows 10 SDK version 10.0.19041.0
[√] Android Studio (version 2025.1.4) [30ms]
• Android Studio at C:\Program Files\Android\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 21.0.8+-14018985-b1038.68)
[√] VS Code, 64-bit edition (version unknown) [29ms]
• VS Code at C:\Program Files\Microsoft VS Code
• Flutter extension version 3.130.0
X Unable to determine VS Code version.
[√] Connected device (3 available) [306ms]
• Windows (desktop) • windows • windows-x64 • Microsoft Windows [Version 10.0.22631.6199]
• Chrome (web) • chrome • web-javascript • Google Chrome 145.0.7632.160
• Edge (web) • edge • web-javascript • Microsoft Edge 145.0.3800.82
[√] Network resources [738ms]
• All expected network resources are available.
• No issues found!
Steps to reproduce
When running our flutter application on this kind of device
iiyama TW2223AS-B2, we noticed that the app runs very slowly, and there is a lot of stutter and lag.So, I have compiled a sample application in release mode to test on this device. I tested this app in two ways: first with Impeller enabled, and then with Impeller disabled. And indeed, when running with Impeller disabled, the app is running smoothly. But when running with Impeller enabled, then the app becomes completely unusable (very laggy; a lot of stutter when scrolling lists; dialogs and images load very slowly; low fps overall). You can check the two live video recordings below.
Note that this device is located in a remote location, so I do not have physical access to it at this time in order to debug the app myself. I can only send and run pre-compiled apps on the device, and ask the person in charge at that location to record the screen for me.
Code sample
Code sample
The code sample from the videos is here: https://github.com/adrianflutur/flutter-iiyama-device-impeller-stuttering-issue/tree/impeller-enabled
And you can switch branches between
impeller-enabledandimpeller-disabledto test both cases.Video demonstration
Video demonstration
You can see both apps running live here: https://drive.google.com/drive/folders/1OpojuMWk6odge1vFk_yO9JaIH5pwGVsg
There are two videos, one for each case: impeller-enabled and impeller-disabled.
What target platforms are you seeing this bug on?
Android
OS/Browser name and version | Device information
Device: iiyama TW2223AS-B2
Full device info
Device Info 3.4.1.3
Date Created 2026-03-11 12:26:31
Device
Device Name : tw2223as-b2
Model : TW2223AS-B2
Manufacturer : rockchip
Device : rk3399_Android12
Board : rk30sdk
Hardware : rk30board
Brand : rockchip
Build Fingerprint : rockchip/rk3399_Android12/rk3399_Android12:12/SP2A.220305.012/eng.pear.20250530.091623:userdebug/release-keys
System
Android Version : 12
Version Name : Snow Cone V2
Released Date : October 04, 2021
Code Name : Android 12L
API Level : 32
Security Patch Level : 2022-03-05
Bootloader : unknown
Build Number : TW2223AS-B2-R08-V3.3-21-N01.1-H1.4-GG-20250530
Baseband : null
Java VM : 2.1.0
Kernel : 4.19.232
Language : English (en_US)
OpenGL ES : 3.2
Root Management Apps : No Apps Detected
SELinux : Permissive
Google Play Services : 26.09.31 (190400-877989800)
Vulkan : Supported (1.3)
Treble : Supported
Seamless Updates : Not Supported
CPU
SoC : rk3399_android12 (no)
no
Processor : Rockchip RK3399
CPU Architecture : 2 x 1.80 GHz
4 x 1.42 GHz
Supported ABIs : arm64-v8a, armeabi-v7a, armeabi
CPU Hardware : Rockchip RK3399 EVB IND LPDDR4 Board lvds (Android)
CPU Type : 64 Bit
CPU Governor : interactive
Cores : 6
CPU Frequency : 2 x 408 MHz - 1800 MHz
4 x 408 MHz - 1416 MHz
GPU Renderer : Mali-T860
GPU Vendor : ARM
GPU Version : OpenGL ES 3.2 v1.r18p0-01rel0.8fe07285d44e34b76128afdd6f13ee46
Battery
Health : Unknown
Level : 0%
Status : Unknown
Power Source : Battery
Technology :
Temperature : 0 °C
Voltage : 0 mV
Network
Type : Ethernet
IP Address : 192.168.1.216
Gateway : 192.168.1.1
Subnet Mask : 255.255.255.0
DNS1 : 2a02:2f04:1d9:8700::1
DNS2 : 192.168.1.1
Interface : eth0
Connectivity
Bluetooth
Bluetooth : Supported
Multiple Advertisements : Not Supported
Offloaded Filtering : Not Supported
Offloaded Scan Batching : Not Supported
Bluetooth LE (Low Energy) : Supported
LE 2M PHY (High Speed) : Not Supported
LE Coded PHY (Long Range) : Not Supported
LE Extended Advertising : Not Supported
LE Periodic Advertising : Not Supported
Wi-Fi
WiFi Standard : Unknown
WiFi Direct : Not Supported
5GHz : Supported
6GHz : Not Supported
NFC
NFC : Not Supported
Secure NFC : Not Supported
Ultra Wide Band
Ultra Wide Band : Not Supported
USB
USB Host : Supported
USB Accessory : Supported
USB Debugging : On
Display
Resolution : 1920 x 1080 Pixels (FHD)
Density : 160 dpi (MDPI)
Font Scale : 1.0
Physical Size : 6.9 inches
Refresh Rate : • 59.0 Hz
HDR : Not Supported
HDR Capabilities : None
Brightness Level : 80%
Brightness Mode : Manual
Screen Timeout : 600 Seconds
Orientation : Portrait
Memory
Random Access Memory
Total : 3836.0MB
Available : 2099.0MB
Used : 1801.0MB
Used Percentage : 45%
System Storage
Total : 0.94GB
Available : 0.00GB
Used : 0.94GB
Used Percentage : 100%
Internal Storage
Total : 22.40GB
Available : 14.27GB
Used : 8.13GB
Used Percentage : 36%
Camera
Thermal
gpu-thermal - 38.8 °C
soc-thermal - 42.2 °C
Sensors
Accelerometer sensor
Vendor : The Android Open Source Project
Type : ACCELEROMETER
Power : 0.2mA
Compass Magnetic field sensor
Vendor : The Android Open Source Project
Type : MAGNETIC FIELD
Power : 6.8mA
Light sensor
Vendor : The Android Open Source Project
Type : LIGHT
Power : 0.5mA
Gyroscope sensor
Vendor : The Android Open Source Project
Type : GYROSCOPE
Power : 6.1mA
Game Rotation Vector Sensor
Vendor : AOSP
Type : GAME ROTATION VECTOR
Power : 13.1mA
GeoMag Rotation Vector Sensor
Vendor : AOSP
Type : GEOMAGNETIC ROTATION VECTOR
Power : 13.1mA
Gravity Sensor
Vendor : AOSP
Type : GRAVITY
Power : 13.1mA
Linear Acceleration Sensor
Vendor : AOSP
Type : LINEAR ACCELERATION
Power : 13.1mA
Rotation Vector Sensor
Vendor : AOSP
Type : ROTATION VECTOR
Power : 13.1mA
Orientation Sensor
Vendor : AOSP
Type : ORIENTATION
Power : 13.1mA
Does the problem occur on emulator/simulator as well as on physical devices?
Unknown
Is the problem only reproducible with Impeller?
Yes
Logs
No response
Flutter Doctor output
Doctor output
Note that this information is from my development device, but the target device (iiyama) is not connected. As mentioned above, that device is not physically accessible to me at this time.