[sirn]

It's also a hardware problem. For example, Alchemist's EUs being SIMD8 but games requiring SIMD16, so it needs to be dispatched to two EUs in a lockstep, or the lack of support for Execute Indirect instruction commonly used in UE5 games, which is currently emulated in software, makes game compatibility a very hit-or-miss.

Battlemage is supposed to fix all these architectural issues. EU in Xe2 is now SIMD16 (which is why the number of EUs per Xe2 core is halved from that of Xe1), and they've added all the previously software-emulated instructions, including Execute Indirect, so in theory Battlemage should be in a much better position in game compatibility side of things.

On Linux side of things, lacking sparse residency support in i915 also contributes to game compatibility[1] (though this is now available under Mesa 24). This is something the new xe driver is supposed to fix, but it's still a long way to go until it's actually usable.

[1]: https://www.phoronix.com/news/Intel-Vukan-Sparse-TR-TT