Hello everyone,
I’m running a Windows 11 virtual machine on Proxmox in order to use Unreal Engine. My physical server has an Intel Xeon Silver 4214R CPU, and I’ve set up GPU pass-through with an NVIDIA A4000 (drivers are up to date and verified via benchmarks).
My issue is that whenever I try different CPU configurations in Proxmox for the VM, Unreal Engine either won’t start at all, or it crashes with an EXCEPTION_ILLEGAL_INSTRUCTION
error. Specifically:
- x86-64-v2-AES: Unreal Engine launches, but immediately logs the
EXCEPTION_ILLEGAL_INSTRUCTION
error. - All other CPU models (including host, cascadelake-server, etc.): Unreal Engine doesn’t start at all.
I’ve confirmed with CPU-Z inside the VM that the virtual CPU passes through the following flags from the physical CPU: SSE4.2, AVX, and AVX2. The GPU appears to be recognized correctly by Windows and is working fine under benchmarks, so I’m fairly confident the issue is CPU-related.
Has anyone experienced a similar problem or found a workaround to ensure Unreal Engine runs correctly in a Proxmox virtualized Windows 11 environment with AVX/AVX2 instructions enabled? Any tips or guidance would be greatly appreciated.
Thank you!