Devran Uenal (@maccosmo), who is working on the Xbox port of KytyPS5, has reported running PS5 games on an Xbox One. The photos he published show gameplay from Quake II and the title screen of MARVEL Cosmic Invasion. The experiment, which had been progressing on the Xbox Series X, has now apparently extended to the older Xbox One. However, the publicly available Xbox build supports only the Series X|S, and the Xbox One is explicitly excluded. The build and settings used in this demonstration have not been disclosed, so it is important to distinguish between the developer confirming that it works and ordinary users being able to reproduce it with the public release.
Xbox One Reportedly Runs Games, but the Public Build Supports Only Series X|S
In a post on X, Devran Uenal said that "some PlayStation 5 games also run on Xbox One" and published two photos of games running. The Quake II photo shows an in-game scene with a weapon raised. In the demonstration the developer published, the game has gone beyond merely launching and showing a title screen, and is actually rendering gameplay.
The two photos, however, show different levels of progress. The top left of the Quake II screen displays 20fps, while the MARVEL Cosmic Invasion photo displays 60fps. But the latter shows a title screen prompting for a button press, so it does not demonstrate that actual combat scenes run at 60fps. Both are also momentary frame rates captured in still images, so they say nothing about sustained performance or whether the games can be played through to the end.
Another point worth noting is the hardware currently supported by the public KytyPS5 Xbox build. On Uenal's GitHub releases page, the Xbox version is described as an experimental build for Xbox Series X|S running in Developer Mode, and the Xbox One is explicitly listed as unsupported. The initial build published on October 11 also stated that it would not run on the Xbox One because it requires the AVX2 CPU instruction set. The follow-up build released on October 19 maintains the restriction to Series X|S.
The differences between this demonstration and the builds distributed on GitHub can be summarized as follows.
| What was published | Target hardware / scene | What can be confirmed and its limits |
|---|---|---|
| Quake II demo photo | The author says it ran on Xbox One. In-game gameplay screen | A momentary 20fps readout. No sustained performance measurement or full-game verification is shown |
| MARVEL Cosmic Invasion demo photo | The author says it ran on Xbox One. Title screen | A momentary 60fps readout. Performance during actual gameplay is unknown |
| Xbox build published on GitHub | Xbox Series X | S in Developer Mode | Xbox One is not supported. The initial build is described as requiring AVX2 |
This table summarizes the author's posts, attached photos, and public release information as of October 19, 2026; it is not a performance comparison of the hardware using the same build. Crucially, the build and settings used for the Xbox One demonstration have not been disclosed. The public release states that it does not run on the Xbox One, yet the author reports having actually run games on one. Explaining this gap would require checking which build was used in the demonstration and how it differs from the public release.
It is therefore not possible to conclude at this point that the public version of KytyPS5 now supports the Xbox One. At the same time, the fact that the public version excludes the Xbox One does not mean that the author's experimental setup is impossible in principle. What the report shows is that, at least in the author's development environment, efforts to run PS5 games on the Xbox One, which is older than the previously supported hardware, are progressing.
Translating PS5 Rendering to Direct3D 12, with Memory Usage Optimizations
KytyPS5, used in this experiment, is an open-source project for running PS5 software in different environments. The original KytyPS5 describes itself as a compatibility layer, mainly targeting Windows and Linux, with experimental support for macOS. It works by replacing the functions PS5 software relies on with ones suited to the host environment, and porting it to Xbox additionally requires adapting it to the Xbox app runtime and graphics features.
The Series X implementation notes published by Uenal document the port to a UWP (Universal Windows Platform) app and the implementation of rendering with Direct3D 12. UWP is a framework for running apps in Windows-family environments. While keeping the parts shared with the original Vulkan implementation, the port converts shaders, the programs that run on the GPU, from SPIR-V to DXIL for Direct3D 12. This conversion uses tools from Mesa, a suite of open-source graphics software.
In other words, porting KytyPS5 to Xbox takes more than changing the app's screens and controls. Even the commands sent to the GPU and the way image data is laid out, read, and written in memory must be adapted to what Xbox offers. The implementation notes record numerous processing changes made to work around limitations of Xbox's graphics features. A game that renders correctly on PC will not necessarily produce the same result through the rendering path converted for Xbox, so verification on real hardware is necessary.
The memory management also includes measures for running games with limited resources. Instead of allocating up front the large memory regions PS5 games expect, the author introduced a scheme that allocates only the regions actually accessed, in 64KiB units. A mechanism was also implemented to swap memory regions that have gone unused for a while out to a temporary file and read them back when needed again. This is meant to bridge the gap between how games expect to use memory and the memory capacity an app is allowed on Xbox.
However, reducing memory usage does not remove the constraint on the CPU instruction set. The Series X implementation notes explain that the public UWP build is compiled for CPUs supporting AVX2 and others, and optimized for the Zen 2 architecture found in the Xbox Series X. The Xbox One's CPU does not support AVX2, so the same executable cannot simply be run on it. Lowering graphics quality or resolution does not resolve differences in CPU instruction sets, so reproducing the Xbox One demonstration would require confirming how this constraint was handled.
Note that the technical explanation so far is based solely on the Series X implementation notes. It is not clear whether the build used in the Xbox One demonstration included the same rendering and memory management features. If the author publishes additional technical information, the changes that made Xbox One operation possible should become easier to understand.
Reproducing It on Xbox One Requires Confirming the Build and Operating Conditions
When running KytyPS5 on Xbox, not only hardware performance but also the system resources allocated to the app matter. Microsoft's UWP system resource allocation documentation sets resource limits for apps running on Xbox depending on their type and how they run. According to the older version of the documentation, the memory cap for a typical foreground app is 1GB, and 5GB when running as an Xbox Live Creators Program game. It also notes an exception: these memory limits do not apply when launching from the Visual Studio debugger.
The public KytyPS5 Xbox version also instructs users to set the app type to "Game" during installation. The author's Series X implementation notes also record an observation that the app's memory limit remained at 5120MB. This, however, is not memory usage measured in the Xbox One demonstration, nor does it indicate the resource limits that applied during it. The resources available change depending not only on the console's memory capacity and CPU performance, but also on which app category and runtime environment are used.
Furthermore, even the Series X port still has unresolved rendering issues. The implementation notes report black speckles appearing on screen in some processing that uses triangle vertex information, and games freezing due to certain image-write operations. The change list also includes items that build successfully but have not been verified in actual operation. Having a feature implemented is different from it working correctly on real hardware, and each game needs repeated verification.
The release of actual gameplay footage from Quake II is concrete progress in exploring how far PS5 software can run on the Xbox One. However, what can be confirmed at present is the author's report and still photos; an environment that ordinary users can reproduce is not yet in place. The next step is to disclose the build and settings used in the demonstration and to continuously verify frame rates, rendering glitches, and freezes in the same scenes of the same games. Once the build and procedure are published and third parties report reproduction results, the range of games that run practically on the Xbox One, and the limits imposed by hardware constraints, should become clearer.