Sequential Stereo and DirectX issues

Development Rendering
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This question was created in reference to: [Sequential stereo is not working with dx12 in [Content removed]

First, thank you Vitalii [Content removed] for trying to help in the past.

We still face different issues when rendering contents on our system(s).

Target system:

Cluster with two PCs, each with 2x RTX 6000 Blackwell and 4x 4K projectors with Mosaic and edge blending. GPU driver is 581.42. Win11

Test system

Cluster with two PCs, each with 2x RTX 6000 and 2x 4K monitors. GPU driver is 581.42. Win11

We performed several tests on the target and test system with dx11 and dx12, with different render modes (mono and frame sequential) and different Sync Policy. We did this for UE5.3, 5.4, 5.5, and 5.6.

We have different undesired behaviors.

  • Render Policy Nvidia causing the application to freeze.
  • No stereo rendering
  • Crashes with certain UE and DX version constellations
  • See attached table

We are wondering if this behavior is due to or setup (2PCs, 2x RTX 6000, Mosaic), if we are completely missing something essential (which I hope) or if it is expected to run into such issues.

Hopefully somebody can help us improve the situation. Thank you, Daniel

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Steps to Reproduce

To verify, we used blank projects and deployed the Unreal projects to the target PCs.

  1. Make new Blank Project
  2. Enable nDisplay plugin
  3. make minimal 2 screen 2 node nDisplay config
  4. Add simple geometry to verify stereo rendering
  5. Copy project to target hardware
  6. Start project with Switchboard
  • With Render API, Render Mode, and Render Sync Policy set accordingly
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Hello Daniel,

We indeed had some issues with the quad buffer in 5.5 and 5.6; however, your tests are showing something different.

Here are my suggestions to try:

  1. Please create project from nDisplay template not a Black project, you might miss certain ini project settings that comes with template
  2. Try 5.7(with fixes for 5.5\5.6) or 5.4(we have few project using this one)
  3. I would suggest to figure out what is going to with Framlock that constantly freezed on your end

To troubleshoot freezes with nv sync policy, could you please provide me with your wiring diagram for the framelock and it was setup for 2 gpus (are you on mGPU or MPMGPU?). Having screenshots for Synchronization tab in nvidia control panel would be great too!

My assumption is something is off with multi gpu and framelock wiring\setup, it shall not freeze.

Meanwhile, I would also strip the system to bare minimum leaving on 1 gpu per PC on test stations.

best,

vitalii