Aerofly FS 4 Vulkan Performance Issue on Intel Iris Xe (Linux Mint)

1st Official Post

    Hi everyone,

    I'm experiencing a severe performance issue with Aerofly FS 4 when using the Vulkan renderer on Linux and I'm interested to know if anyone else has seen similar behaviour.

    System Information

    • HP ZBook G8
    • i7-1165G7, Intel Iris Xe Graphics (Tiger Lake GT2), 32gb ram
    • Linux Mint 22.3 (latest version)
    • Native Linux version of Aerofly FS 4 via Steam
    • Not using Proton

    Graphics Information

    OpenGL:

    • OpenGL Renderer: Mesa Intel(R) Iris(R) Xe Graphics (TGL GT2)
    • OpenGL Version: 4.6 (Compatibility Profile)
    • Mesa Version: 25.2.8-0ubuntu0.24.04.1

    Vulkan:

    • Vulkan Instance Version: 1.3.275
    • Vulkan API Version: 1.4.318
    • Driver: Intel open-source Mesa driver
    • Device: Intel(R) Iris(R) Xe Graphics (TGL GT2)

    Issue

    At 1920x1080:

    • OpenGL runs at approximately 50 FPS and is perfectly usable (But does have some issues with textures flickering)
    • Vulkan runs at less than 1 FPS at any airport in any aircraft
    • CPU usage becomes extremely high when Vulkan is selected.

    The performance difference between OpenGL and Vulkan is dramatic, despite using the same hardware and settings.

    Troubleshooting Performed

    • Confirmed OpenGL is using the Intel Iris Xe GPU.
    • Ran vkmark Vulkan benchmark successfully.

    vkmark results:

    • Vulkan device detected: Intel(R) Iris(R) Xe Graphics (TGL GT2)
    • vkmark Score: 7652

    This suggests Vulkan is functioning correctly on the system outside of Aerofly FS 4.

    Question

    Has anyone with Intel Iris Xe graphics or a similar Intel/Mesa Linux setup experienced extremely poor performance when set to Vulkan in Aerofly FS 4 while OpenGL performs normally?

    I've already contacted support but have not heard anything back.I am happy to provide logs if needed.

    Thank You

    Edited once, last by flyaway99 (June 19, 2026 at 5:51 PM).

    Attached is the tm.log

    Looks like it is defaulting to cpu software rendering :(

    tmrenderer_vulkan: device: name='Intel(R) Iris(R) Xe Graphics (TGL GT2)'
    tmrenderer_vulkan: device: name='llvmpipe (LLVM 20.1.2, 256 bits)'
    tmrenderer_vulkan: using device 'llvmpipe (LLVM 20.1.2, 256 bits)'

    I've tried to launch steam with 'MESA_VK_DEVICE_SELECT=8086:9a49 steam' however it still uses llvmpipe.

    Any creative ways to force rendering on the Intel Iris under linux?

    • Official Post

    Sorry for the late reply. It seems like the llvmpipe Vulkan driver reports more 'features' and better data than the Intel Iris driver.

    On Linux you can ( depending on your distribution ) configure what drivers are reported or not. This really depends on your distribution, so please search the web.

    On Debian based system you can do this:

    Code
    # liste available vulkan ICDs
ls /usr/share/vulkan/icd.d/

# force a specific ICD via environment variable
VK_DRIVER_FILES=/usr/share/vulkan/icd.d/radeon_icd.x86_64.json vulkaninfo --summary

    Thanks, yea I suspect it is detecting total system memory or something dumb like that. If you have a bug tracker, can you log that please as it's an out of the box headache which may catch others users.
    ls of '/usr/share/vulkan/icd.d' produced the following JSON files

    Code
    asahi_icd.json         intel_hasvk_icd.json  lvp_icd.json      radeon_icd.json
gfxstream_vk_icd.json  intel_icd.json        nouveau_icd.json  virtio_icd.json

    Under steam launch options for FS 4 I entered VK_DRIVER_FILES=/usr/share/vulkan/icd.d/intel_icd.json %command%

    Just an observation, not sure if Vulkan renders in higher quality, but I had to reduce the graphic settings once in Vulkan to get steady framerates which previously worked well in OpenGL.

    I'm happy. This can be closed.