Also tested the same setup (Drivers, Proton, CashyOS) on different device (Laptop with RTX 3060 Mobile and 6GB VRAM) and Forza Horizon 5 and Hunt: Showdown (on low) doesn't use more than 3GB VRAM (so in system monitor it says it uses 5GB, but it allocated 3GB to VRAM and other to GTT), so it seems that low VRAM and VRAM may not be the problem(?)
None of us have that old AMD GPUs for testing, so not sure what can be done. Does it reproduce on Polaris 4GB?
I don't know, I actually by accident have two second GPUs, both Polaris, 4GB and 8GB, but they are under repair, and I will probably have only 8GB left, and they can be problematic. I will write as soon as I will be able to test on them and if they will work properly.
VKD3D_CONFIG=log_memory_budgetx1 2025-12VKD3D_DEBUG=infox1 2025-12VKD3D_LOG_FILE=".../vkd3d_hunt.log"x1 2025-12
Playing Forza Horizon 4/5 with high VRAM usage causes bugs with drivers: unable to flush VRAM; infinite VRAM allocation until all VRAM, RAM, ZRAM, SWAP is filled;
Logs for vkd3d I got with
VKD3D_CONFIG=log_memory_budget VKD3D_DEBUG=info VKD3D_LOG_FILE=".../vkd3d_hunt.log" %command%Steam launch optionsHunt: Showdown 1896
(Bug turned out to be with mesa drivers)
*Logs for vkd3d when VRAM Usage Target 70%
vkd3d_hunt_showdown_90.log
Forza Horizon 4/5
When logged and pressing Start (loading map) (using any Proton versions) it starts to allocate infinite VRAM (in system manager it increases up to >40gb graphical memory and when SWAP partitions starts writing system is extremely laggy and can freeze forever or restart). Closing game or killing process completely frees memory and system is in previous state.
*Logs for amdgpu and vkd3d
amdgpu_forza_horizon_1.log
vkd3d_forza_horizon_1.log
Letting it to run for longer and new line (third) starts appearing time to time
-01a8:info:vkd3d_memory_transfer_queue_flush_locked: Clearing allocation 1037: 24576.
-01a8:info:vkd3d_memory_transfer_queue_flush_locked: Clearing allocation 1038: 49152.
-01a8:err:vkd3d_memory_transfer_queue_flush_locked: Failed to submit command buffer, vr -4.
-01a8:info:vkd3d_memory_transfer_queue_flush_locked: Submitting clear command list.
-01a8:info:vkd3d_memory_transfer_queue_flush_locked: Clearing allocation 0: 354304.
Forza Horizon has huge memory leaks and unable to flush VRAM, because I catched similar memory leaks (maybe?) in laptop with the same setup (Drivers (except videocard drivers), Proton, CashyOS), but with RTX 3060 Mobile, but it just was able to flush VRAM and after map loaded game behaved normally.
vkd3d_forza_horizon_rtx_3060.log
Software information
Forza Horizon 4
Forza Horizon 5
System information
(No overclock)
(I've tried Proton 8, 9, 10, hotfix, experimental, CashyOS Proton, Proton GE)
Log files
steam-xxxxx.log weights 4-10 gb with this bug, so can't attach