Multi-gpu crash (DX12)

Nsight graphics crashes whenever I try to capture a frame from my DX12 DXR application. The problem only arises when I use NSight with two GPUs (no SLI) plugged into my system. This problem doesn’t arise with a single GPU, even though the application is only using one of the GPUs. My application doesn’t crash when it runs without nsight, and the crash dump only displays NSight calls.

The GPUs i’m using are a 3060ti and a 2080ti, the displays are connected to the 3060ti.
System: Windows 10 with SDK 10.0.19041.0

Dump file:
c468e957-887c-4fdf-a1a4-07562a926457.dmp (247.1 KB)

Hello,
Thank you for using Nsight Graphics. I’m sorry you ran into this issue. I’ll create a bug for the issue you described and have our engineering team investigate. If need any additional details then someone from our team will get back to you.

Regards,

Hi lajbrands,

I took a look at the dump that you shared and it looks like the nvidia driver is crashing due to the commands that Nsight issues. Is there a particular view you are opening that is causing the crash? I am wondering if it is the acceleration structure view, for example, because I see that the crash is happening during a vulkan instance creation.

One additional challenge is that I’m unable to fully resolve the callstack. I am seeing some graphics-hook64.dll from obs as a part of the callstack, and this looks suspicious. Are you running obs while you try to debug? I’ve used obs myself to capture videos of Nsight, but never under multi-gpu, and I wonder if there is an issue there. Any additional steps you could take to debug whether obs is interfering would be useful.

Thanks,

Dan

Hi Dan,

The crash happens upon frame capture, before I’m able to open any sort of view. Something that I have been able to verify with my office computer is that a dual-gpu setup with two similar GPUs (2x 3090, no SLI) does not run into this issue.

Regarding your other question, I’m not running OBS but I believe OBS does add implicit validation layers which are probably what you’re seeing on the callstack.

Thank you,
Leon

Hi Leon,
Is it possible for us to get access to your app so we could potentially be able to repro the same scenario? If so you can communicate with me at dwoods@nvidia.com. Our engineer tried and couldn’t repro it using a simple DXR sample (D3D12RaytracingSimpleLighting) on RTX3070 + RTX2080.
Regards,