[Feature] X server ↔ Android Surface synchronization and frame pacing Improve

[hansm629]

Problem description

@twaik

Hello sir,
I’d like to ask about improving synchronization and frame pacing between the Termux-X11 X server and the Android Surface.

As far as I know, most currently released Wine-based Android Apps(Winlator, GameHub, GameNative, and MiceWine) use an X server based on Termux-X11.

With Snapdragon 8 Elite Gen 5 and the newer mesa Turnip driver now available, Android devices have reached a level where running PC games is realistically possible. As a result, new issues are appearing that weren’t noticeable before when the framerate was lower.

What steps will reproduce the bug?

Specifically, even though the framerate and ping shown in DXVK_HUD / VKD3D_HUD look stable, the actual on-screen motion is not smooth and shows noticeable stuttering (frame pacing issues).

Examples:

• 1280×720: HUD shows 50–60 FPS → on-screen feels like ~25–30 FPS, with intermittent stutters
• 1920×1080: HUD shows 25–30 FPS → on-screen feels like ~10–15 FPS, with intermittent stutters

My guess is that this is related to synchronization and frame pacing between the X server and the Android Surface.

I’ve also observed a similar issue even in the Termux bionic native environment: running Supertuxkart through the Termux-X11 X server shows the same kind of stutter despite stable FPS reported by the HUD.

In the mid to long term, is it possible to improve synchronization and frame pacing between the X server and the Android Surface?

Thank you for your time, and I’d appreciate your review.

What is the expected behavior?

No response

[ziad9267]

This happens for me as well, it gets noticeable when i'm on low framerate.

I found two workarounds for this, either limiting the FPS to my screen's hz or use MESA_VK_WSI_PRESENT_MODE=immediate and set max image count in swapchain to 1, last method seems to be good enough but hurts performance a bit.

[twaik]

Winlator, GameHub, GameNative use old exagear-based X server, not related to termux-x11.

[hansm629]

@twaik
Oh, I see.
Thank you for correcting that.

But I heard that some Winlator branches use the Termux-X11 X server. Was I mistaken about that?

I also remember that, back when Winlator glibc was popular, some Mesa Turnip branches for Winlator glibc had the Termux-X11 DRI3 patch applied.

In MiceWine’s case, the developer clearly told me that it uses Termux-X11 as its X server. Also, when running SuperTuxKart natively on Termux bionic, I see a similar stuttering-like symptom where the reported frame rate is high, but the actual on-screen motion does not look smooth.

Do you think this kind of issue could be improved in the future?