Drastically different performance between Quest 1 and Vive Focus Plus headsets

[DjOxvear]

We've been working on an application in Unity using the XR framework, targeting different headsets. Originally developing towards the Quest 1, recently we have ported the project to Vive (minimal work required due to XR framework support) and found that the performance is vastly inferior to what we were seeing on the Quest, despite very similar hardware specs.
While the Quest 1 happily runs around 72 fps, the Focus Plus easily dips into the 60's, and sometimes even goes south of 50 fps. This is entirely down to GPU performance.

Looking into the profiler, it appears the Vive is rendering an awful lot more for the same scene and viewing point/direction:

The render counts are almost 4 times that of the reported numbers on Quest. For reference, the Quest numbers are similar to what we're seeing on PC, while the Vive numbers are unrealistic and completely off the charts.

Rendering is configured as Single pass on both targets, though even that wouldn't account for the perceived x4 increase in overhead.

Any idea what's going on here?

 

The builds are made from the same scene and project, with no differences except for which XR plugin is active.
Project context:

• Unity 2019.4.18f1 LTS
• XR Plugin management 3.2.17
• Wave XR Plugin 1.0.1
• Oculus XR Plugin 1.7.0
• XR Rig prefab
• Release build for both targets

Edited April 16, 2021 by DjOxvear
ctrl+enter submitted post before finishing

[Tony PH Lin]

Hi @DjOxvear,

Thanks for clarifying this issue and report with us.

Just take here as a reference to share if more developers have encountered similar issue so they can get the answer right away.

We have fixed this Occlusion Separation Sphere issue inside our plugin from 4.0.0 hot fix (R39).

Thanks.