Optimizing Cemu
Required Reading
For the best performance, we’ll be switching the default graphics API from OpenGL to Vulkan. While less stable, Vulkan tends to run faster and has extra features in Cemu which OpenGL doesn’t.
Asynchronous Shader Compilation
When running games in Cemu, graphical shaders need to be re-compiled to work on a desktop GPU. This can take some time, which causes small stutters in the game every time a new one is sent to the emulator.
Doing this asynchronously allows the emulator to run the process in the background. This means that when the shader is first called, it skips being rendered to the screen, and is instead stored for the next time it’s used, providing a much smoother experience.
The video below shows loading Breath of the Wild for the first time using asynchronous shader complation. After these shaders have been recompiled and cached, they won’t need to be converted again, so the graphical glitches stop.
Asynchronous shader compilation in Cemu v1.19.2b
VSync Matching
Vulkan also allows us to use a new experimental VSync technique which allows Cemu to use the game’s built-in frame-pacing instead. This avoids tearing and reduces input latency compared to previous methods.
Cemu Settings
- Open the Cemu main menu
- Click
Options
->General settings
on the top bar - Navigate to the
Graphics
tab - Change the “Graphics API” to
Vulkan
if it is not already- If this doesn’t appear, or you have problems using Vulkan, read the OpenGL Optimization Guide
- Ensure that your “Graphics Device” is set to use your most powerful GPU if your device has dual graphics
- Set “VSync” to
Match emulated display (Experimental)
- If you use a display with variable refresh rate (G-SYNC), set this to
Off
instead - This feature is experimental and may cause issues
- If you use a display with variable refresh rate (G-SYNC), set this to
- Enable
Async shader compiler
- Navigate to the
Audio
tab - Under
General
, change “API” toXAudio2
Cemu should now be running the fastest it can, with a huge increase in performance for some users. There are even more ways to improve framerates in Breath of the Wild. Follow our optimization guide for more info.
Continue to Optimizing Breath of the Wild (Optional)