120HZ mode frame rate drop

[zeroonedeveloper]

So I have a game running on Quest 2 that runs at (according to OVRMetrics)

72fps when the refresh rate is set to 72Hz, GPU 84

80fps when the refresh rate is set to 90Hz, GPU 97

But drops to

65fps when the refresh rate is set to 120Hz, GPU 87

The device has 120Hz refresh rate set under experimental features

Anyone know why this is happening?

If the game is just in a menu screen (fewer draw calls) the fps matches the Hz

Unity 2019.4.34

[baroquedub · Accepted solution]

Seems to me that you've answered your own question... your game is struggling to play at 120fps. The way VR frame timing works, if you go over your GPU budget by as little as 0.1 ms it will simply not render the next frame and halve the frame rate. Asynchronous TimeWarp will try to smooth things out but you've got be be working within your frame budget. Simply enabling 120Hz refresh rate isn't going to give you that performance, it's just unlocking the potential.

[zeroonedeveloper]

Thanks.

I kind of get it, at 120Hz it's got to try to render 30 or 48 more frames per second so the device is doing more

I was hoping that it would just drop the Hz to an acceptable rate (back to 90 or 72) instead of halving the frame rate