Oculus Quest 2 - Newbie Need Help

[Voithe]

Hi guys! I've just got my hands on an Oculus Quest 2 and i have various questions but... let's start with:

How many FPS should i achievie on the default scene with one girl and 3 light? My PC specs are: GPU GeForce GTX 1080, CPU Intel i7 6700K, RAM 16 GB DDR4.

It seems that i can't get above 35 FPS... i don't know if this is the max that i can get. Even if i change settings it seems to have no impact... like it is somehow locked.



That said, since i'm a real newbye in VR in general, any tips whould be really appreciated.

P.s. Sorry for my bad english... i hope you understand what i've wrote... XD

 

[Cat]

Hi!

I can't say exactly how many fps you can expect. But I can say that you are correct with the locked fps.
I guess you are using the Quest with an Oculus Link Cable for PCVR. As far as I know this connection is currently locked to 70 fps.
To give you a clear image (no tearing), the fps will be locked to this value even if your computer would be able to deliver more frames. If your system is not able to deliver 70+ fps, then the software will fall back to half the fps -> 35 fps!
Oculus (or SteamVR) will then calculate/interpolate 'fake' images for every second frame. So your VR screen will still refresh with 70 fps even if your computer can't handle the graphics. This comes at a slight cost of visual fidelity and tracking performance.

So in short your Quest 2 will use the native refresh rate (currently 70hz with Oculus Link) if you get more than 70 fps in VAM or half the refresh rate if you are below 70 fps.
Oculus will unlock 90 fps (for Quest 2) at a later date. Then it would fall back to 45 fps.

I have an Oculus Rift S with 80Hz refresh rate, an RTX 2060 and an i5 f.e. When I spawn more than one person, use certain clothing or am running intensive plugins/scripts, then it will fall back to 40hz really quick.

Personally I don't mind the 40 fps I get though. I prefer the visuals and physical interactivity more than a smooth or better tracked image.
But deactivating or lowering certain physics (body, hair and clothing!) may help. Use the performance monitor in the settings to find the 'bottleneck'! If you can reach high enough frames, your fps should jump to 70.

 

[Voithe]

Many Thanks for the technical explanation! It was exactly what i'm looking for... and i can confirm all what you wrote...

Now... i'm just curios about why it switches from 70 to 35... and not all the fps rates between... ?
But it's just my curiosity...

 

[Cat]

A screen has usually a fixed refresh rate. Especially for VR you want a consistent update rate because you would feel the difference if your fps drop from 70 to 50 for a few seconds for example.
But if your Quest is set to 70hz but your PC delivers 60 fps for example, then the screen on your HMD would show an image for slightly more then one frame. Then the PC pushes the next image to the device. If there was movement between the two images, you may see a seam between the images. This is called 'screen tearing'.
You can search for the term 'screen tearing' for a better explanation than mine. ?

Edit/Addition:
So to avoid screen tearing while keeping the refresh rate at 70hz, your PC renders at 35 fps (or half the refresh rate) if it can't reach the full 70 and calculates the images inbetween. This ensures exactly 70 pictures for each seconds.
And if the PC could handle more than 70 fps, it would be locked at 70 fps for the same reasons.
This is the same for all current VR-Headsets. Only the refresh rate differs from each device or setting.