GPU Frame Timing on IOS/Android 2019

I'm trying to implement Dynamic Resolution Scaling using XRSettings.renderViewportScale to get a smoother framerate on a cardboard-enabled project in Unity 2019.1.0f2.

However, I'm not getting any GPU-Timings.
Tried:
- XRStats.gpuTimeLastFrame (deprecated, returns 0)
- XRStats.TryGetGPUTimeLastFrame (returns 0)
- FrameTimingManager.GetGpuTimerFrequency (returns 0)
- FrameTimingManager.GetLatestTimings() (returns 0)
- XRDevice.refreshRate (returns screen refresh-rate, not current speed/fps).

I've tried this in builds on both Vulkan and OpenGL 3, on a Mali GPU (Oppo F7), and an Adreno one (Galaxy S8), but I'm not getting ANY results anywhere..
Is this a bug in Unity 2019? The docs clearly state that the FrameTimingManager should be working for Android (Vulkan) and IOS (Metal) right now.

 

I'm not actually looking to change the framebuffer resolution, just the section of the buffer that's used (which is why I'm looking at XRSettings.renderViewportScale https://docs.unity3d.com/ScriptReference/XR.XRSettings-renderViewportScale.html )..
Currently, my CPU-frame is taking about 5-8 ms.
However, my GPU (on the Oppo) is taking anywhere from 16.5 to 18ms (narrowly missing VSync, thereby limiting to 30fps). I have narrowed this down to fill-rate, but since I have near-zero overdraw (I'm rendering 1000's of quads using ECS), I'm looking at scaling down the resolution just a tiny bit, in order to cut my render-time by just enough so that I can stay at 60fps throughout.
As the GPU differs per device, I'm trying to implement a system which can scale from 0.7 (for a poor device) to about 1.4 (for e.g. an IPhone X). In order to do this, I'd need the GPU-Timings to check how close I am to getting that <16ms render, to prevent the VSync.

As Vulkan isn't currently supported with XR, and OpenGL doesn't have FrameTimingManager, is there any way I can get the duration for Rendering? (Aside from strictly relying on FPS-count?)

 

I ended up using FrameTimingManager on IOS, and a library ( https://github.com/google/render-timing-for-unity ) for android..
Unfortunately the RenderViewPortScale didn't actually work correctly on IOS (it actually changes the display-size (showing less)), so I had to use eyeTextureResolutionScale (which is heavy) on IOS..

My result/test-example can be found at:
https://github.com/frankvHoof93/FrameTimingTest

 

So, what is the status of the FrameTimingManager on Vulkan now? I am running on 2018.4.21f1 and I am getting no frame times on Vulkan! While it does clearly stake that it should work on that version. Will there be a backport anytime soon?

 

Hmm, I updated the project o 2019.3.10f1 and I am still getting 0 from the gpu and cpu frame times. Bummer