DX12 + XR + HDRP seems really bugged

Unity Engine
,
1

Hi,

wanted to try out DX12 and check performance compared to DX11.
With my test setup (HDRP+ DX12 + OpenXR + Unity 2023.1.7b) I ran into lots of issues:

  • very varying performance (in my test scene between 8ms GPU time and 50ms GPU time on repeated runs).
  • lots of crashes; in best case just crash of Unity Editor, in worst case crash of my PC (which basically never happened before).

No issues with DX11 on same setup.

1 Like
2

Update: after some restarts / driver update it seems to run more stable (performance and overall stability).
Performance under DX12 is still worse then DX11, both in simple and complex scenarios. As the delta seems to be linear, I guess the overall HDRP / OpenXR overhead makes DX12 perform worse then DX11. I measured around 2ms GPU rendering time difference, even in near empty scene (with a 3080).

3

Same issue. Wanted to try DX12 in my HDRP project with OpenXR. As in your case, the performance varies from ~1X to ~7X FPS seemingly randomly both in Editor and Build.

4

same in unity 6

5

Did someone make a bug report for this

6

several. procedure goes always like this: QA is rephrasing the report, so that no one understands what this report was about; probably because “performance” is not worth a ticket. ticket will then sit there untouched. if this takes too long, i do a new report.

7

Hmm interesting, I have had quite good results and even fixes with performance reports if there is a simple repro

8

it depends a bit on who’s your assigned QA guy at Unity. They seem to have several junior ones.
This is my most recent issue about GPU performance in DX12/XR, reported in February:
https://issuetracker.unity3d.com/issues/quest-low-gpu-performance-with-directx12-when-compared-to-directx11

1 Like