Two display backends, one handheld

X11 is the mature path every Bannerlator game has used until now. Wayland is a second backend that runs Windows games through a compositor Bannerlator carries itself. This deck compares the two as they stand after pre-release 9, lists what shipped, shows the measured zero-copy result, real HDR and games on a TV, and is honest about what is left.

Most numbers and claims here come from one device, an AYANEO Pocket FIT with an Adreno 750. The OpenGL fix for phones with no display device and real HDR were also proven on an Adreno 840 phone. Games on a TV were proven on the Pocket FIT with HDR TVs.

Where a frame goes

The zero-copy row is real since pre-release 2, behind the BANNER_WAYLAND_ZERO_COPY=1 flag: the game's driver builds its swapchain on Android gralloc buffers and the compositor passes them to the display hardware untouched.

Frame rate today

With the default copy path Wayland is not a frame-rate win. Vulkan and D3D12 sit about 20 percent behind X11 because the compositor copies every frame once; the DXVK paths are within a few percent; The OpenGL row is not a native OpenGL result: the AIO test draws that row through a Vulkan swapchain on Wayland. Native OpenGL games render on Wayland since pre-release 6. At hundreds of frames per second one copy shows up hard. In a GPU-bound game at 40 to 60 fps the same copy costs well under half a millisecond, a few percent either way. Half-Life 2 sits at the 144 Hz cap on both. Pre-release 9's compositor work (phase 1) lifted the copy path on this device against pre-release 8: Vulkan +9%, D3D12 +12%, DirectDraw +20%, D3D11 +3.5%, with higher 1% lows on every API.

Half-Life 2, same scripted intro scene, two 60-second passes per mode alternating, GPU and battery sampled once a second. Frame rate did not move because the game is CPU-bound under FEX on this device; the compositor's GPU work did go away. A frame-rate gain needs a GPU-bound game or a large panel.

What each backend can do right now

Everything since 3.1.1

Real HDR on Wayland

On an HDR screen, highlights can go brighter than normal white and colours reach further. X11 has no way to do this at all. On Wayland the game's 10-bit HDR frames go straight to the display hardware, tagged so the phone shows them as HDR.

Tips. Don't screen-record or take screenshots while judging HDR: Android turns the HDR boost off while it captures. A hot phone loses it too; the session log now says which. The drawer's "HDR" screen effect is a different thing: a bloom filter on a normal picture, not HDR output.

Eight Turnips, six sources

All eight are rebuilt from those sources as Wayland, Linux drivers with the KGSL backend and Wayland WSI. The Android zips those projects publish cannot run inside Proton. Vauzi recommends TU_DEBUG=sysmem on 710, 720 and 722 if you see artifacts. All eight load and render on the 750; the a8xx builds now run on real Adreno 830 and 840 phones; the 7xx builds have not met their own silicon yet.

How a tester gets going

Root causes

• API switchSwitching graphics APIs killed the session because the bundled Termux Turnip could not survive a device destroy and re-create. Fixed by building our own Wayland Turnip. The same driver swap fixed DiRT Rally 2.0 stalling on its splash.
• Layer nameA Proton named 11.0-2-wayland would have silently fallen back to Proton 9 in every shipped build: the layer-name parser only accepts version, subversion and architecture. The Wayland layer became line 11.0-2.1, which parses everywhere and is never offered as an update to stock 11.0-2.
• Keyboard 1winewayland gave up its keyboard entirely when the xkb registry data was unreadable, and the bundled registry library pointed at Termux's private folder. The registry is now optional.
• Keyboard 2The compositor gave keyboard focus to Wine's desktop surface, so every key was queued to explorer's thread instead of the game. Keys now go to the window you clicked.
• Buffer churnDestroying a committed buffer, which every swapchain rebuild does, produced a black frame and a window close and reopen. The compositor now keeps the last image until the next commit.
• Lock contentionSwapchain calls were held under the same lock the UI thread needs. Backgrounding mid-game risked a freeze; the UI thread now hands the surface over without waiting.
• Shortcut namesAn executable without a folder or without .exe crashed the launch in two places. Fixed.
• First launchThe first launch after installing a layer opened at 1024x768: Wine's prefix update ran inside the session's first process, its helper desktop was killed at once, and the display cache fell back to a default rectangle. The update now runs before the session.
• OpenGL blackNative OpenGL games were a black window with sound: the compositor advertised an older buffer-sharing protocol than Mesa's EGL needs to find the GPU, and the layer then steered OpenGL into a software renderer it does not contain. Fixed in pre-release 6.
• OpenGL vanishOpenGL games disappeared seconds in with no error: Mesa's threaded helper faults on a thread Wine does not manage, so no handler reports it. Safe mode turns the helper off; the crash itself still needs a driver rebuild.
• Create screenA new container dropped the display backend and the Wayland game driver: three hand-kept lists of what a save writes had drifted apart. Create, edit and the defaults now share one writer.
• Control PanelThe v7 XP Start menu opened the Control Panel folder through a new explorer, which mangled the folder's special name and quit. The entry now starts control.exe.
• Desktop closeWine's desktop closed a second into a 32-bit game's startup: this Proton tree closes a desktop with zero grace instead of upstream's one second, and the thread count matched by coincidence. The grace is restored in the layer and every session process now starts on the game desktop.

What is left

1. Turn zero-copy on by default once more GPUs have run it, and measure it where it can show: a GPU-bound game and a large panel. Both performance paths are in and proven.
2. Real 710, 720, 722 and 8xx testing of the eight bundled drivers. The most valuable thing a tester can send.
3. Guest-side leak on every API switch, a few dozen file descriptors and threads. X11 leaks more, so not Wayland-specific.
4. Screen effects on GPUs whose buffers the compositor cannot import, now within reach thanks to the display-layer machinery.
5. Fix the OpenGL threaded-driver crash itself so safe mode can default to off. Needs a driver rebuild that can report a fault on a thread Wine does not manage.
6. HDR in more games and on more phones (slide 6). See RE Engine HDR on an HDR screen, have Unreal Engine HDR write the game's ini lines itself, add per-engine presets and scRGB, and prove the HDR boost request on phones like the ROG Phone 9 Pro.
7. Finish the TV tab. Prove Home and reopen during a TV game, match resolution and the output-mode picker, and hand input back to the TV by itself.
8. Mali and other non-Adreno GPUs. Wayland needs a game driver built for it, and today that means Turnip, so Mali phones stay on X11. The likeliest route is the Vulkan wrapper Mali users already run on X11, rebuilt for Wayland.

What Wayland can do that X11 can't

Or can't do well. A few of these have a weaker X11 version; none of them work as well there.

Working on Wayland today

Possible with Wayland, not built yet

In general

What to tell people

Pre-release 9, not offered by the in-app updater. 3.1.1 stays the stable release.