Xbox Series X Runs PS5 Games in Dev Mode, Memory Capped

In a YouTube video posted on September 8, developer Devran Cosmo Uenal booted the PlayStation 5 version of Quake II on an Xbox Series X and played it with an Xbox controller. The build ran through PS5X, Uenal's Xbox port of the open-source PS5 emulator KytyPS5, and he says he has since got three more PS5 titles working.

The technical feat is real — but its practical use is limited. PS5X only runs in the Series X's official Developer Mode, where Microsoft's documentation restricts games to 5GB of memory. That cap rules out the majority of current-generation titles, and there is no public PS5X download for others to try.

How PS5X works

Sony and Microsoft built the PS5 and Xbox Series X on closely matched AMD foundations: eight Zen 2 CPU cores, RDNA 2 graphics and 16GB of GDDR6 memory. PS5 games are compiled for x86-64 processors, so KytyPS5 can run their code on a host CPU rather than emulating the PS5 hardware instruction for instruction. Its developer describes KytyPS5 as a compatibility layer that translates what a PS5 game asks for into something a PC can execute.

KytyPS5 converts the PS5's graphics commands and recompiles shaders for Vulkan, which on PC requires a Vulkan 1.3 capable GPU. Xbox Developer Mode supports only DirectX 11 and DirectX 12, so "Since Vulkan isn't supported, everything needs to be translated to DirectX," Uenal wrote in the YouTube video's description, adding that AI assisted parts of his effort. As VideoCardz noted, that means fixes the KytyPS5 PC renderer receives must be adapted again before PS5X can use them.

Uenal calls PS5X a "research project" for "running PS5 homebrew and game backups" on a Series X in Developer Mode and says the build does not include any PS5 firmware or decryption keys. KytyPS5's documentation advises users to stick to game files they have obtained legally. Emulation projects have legal and commercial risks: the Switch emulator Yuzu was effectively ended after its makers settled a Nintendo lawsuit in 2024 for $2.4 million. The RPCS3 team lists KytyPS5 and SharpEmu as the two active open-source PS5 emulators able to boot games and warns of scam sites posing as legitimate projects.

At the time of Uenal's video, PS5X runs the PS5 versions of the GEX Trilogy, Hellboy: Web of Wyrd, Marvel Cosmic Invasion and Quake II, and all four accept Xbox controller input. Some have working audio. TweakTown estimates Quake II in Uenal's footage runs at roughly 25 to 45 frames per second. Those four games are also sold on other platforms, so there is no evidence yet of PS5X handling a PS5 exclusive; Uenal himself stresses that compatibility is limited and early.

PC-side PS5 emulation is also progressing. Android Authority reported on September 28 that KytyPS5 can go in-game on a variety of PS5 titles on high-end PCs, and that one user showed Marvel's Wolverine reaching its main menu in slow motion on a machine with an NVIDIA RTX 5090. That clip did not show gameplay, and it was unclear whether the setup used a standard emulator build. Any PC progress must be rebuilt for DirectX and squeezed into the Xbox's much smaller memory budget before PS5X benefits.

Microsoft sets firm memory limits in Developer Mode: games are capped at 5GB, and apps at 1GB, with any request for more memory failing. By contrast, a retail Series X title can access about 13.5GB of the console's 16GB, the remainder being reserved for the system. The 5GB Developer Mode cap leaves PS5X with roughly 37 percent of the memory a retail Xbox game can use. Microsoft will lift the cap when software runs under the Visual Studio debugger, a configuration meant for developers testing code.

Microsoft blocked emulators in Xbox's retail mode in 2023 under a store policy that bans products emulating a game system, and the company reportedly issued 15-day suspensions to players who found workarounds. Since then, players wanting to run emulators such as Dolphin have relied on Developer Mode, though a console in that mode cannot load retail games until it is switched back.

For now, PS5X is an intriguing technical demonstration rather than a practical option for most players. There is no public distribution, the Developer Mode memory cap prevents large current-generation games from running, and without a jailbreak there is no clear workaround. Watch for scams as well: attackers have tried to capitalize on interest in these projects by releasing malware under similar names, for example PCS5X.