Ticking/Unticking Interleaved + Async Boxes in Steam VR Not Necessary for Rift Users

[F4CEpa1m]

Hi all  🙂    

It has been suggested that Rift users should untick the Interleaved + Async Reprojection boxes in Steam VR:

https://i.imgur.com/38uC0Gz.png

I actually thought this was the case too but it looks like these boxes have no effect for Rift users.    

Basically, Steam VR doesn't do any of its own reprojection when a Rift is connected, so those boxes do nothing.         

This is because Steam VR passes all the textures to the Oculus runtime, and then the Oculus runtime handles all of the reprojection via its own ATW + ASW after the fact, which is confirmed here: 
https://steamcommunity.com/app/250820/discussions/0/305510202679681031/

This is confirmed when we see that Steam VR's performance graph doesn't drop frames at all when a Rift is connected no matter how hard the Super Sampling is pushed in Steam VR.  But you will see dropped frames in the Oculus debug tools Performance HUD:

https://i.imgur.com/mXyFf5O.png

/u/phoenixdigita1 over on reddit initially tested this when looking at the dropped/reprojected frames counter in the Advanced Settings app and confirmed it:
https://www.reddit.com/r/SteamVR/comments/8ei934/calling_all_rifters_raise_your_hand_if_steamvr/dxxj...;

I ran my own tests and confirmed the same:
https://www.reddit.com/r/SteamVR/comments/8ei934/calling_all_rifters_raise_your_hand_if_steamvr/dxxm...

Here are the comparison shots from those tests:    

Both boxes UNTICKED, 2.0 SS in Advanced Settings:    

https://i.imgur.com/1oQRFFR.png ;    

Both boxes TICKED, 2.0 SS in Advanced Settings:     

https://i.imgur.com/aWMEmqq.png ;   

Steam VR 4.0 SS Boxes UNTICKED SteamVR Performance Graph:       

https://i.imgur.com/11M7654.png ;       

Steam VR 4.0 SS Boxes TICKED SteamVR Performance Graph:       

https://i.imgur.com/mXyFf5O.png ;     

Ignore the slight performance differences due to the moment that I took the screen grab.      

The point is, Steam VR doesn't use it's Interleaved + Async Reprojection tech at all when a Rift is connected, the Oculus runtime handles that on its own, so ticking/unticking those boxes in SteamVR is redundant.      

And while it's no big deal if they are or aren't ticked, I figured some of you would like to know for certain  🙂     

x_0

[elbo]

Thanks, always wondered about this. I have seen on a few threads that some people start steamVR games without letting the oculus software open (not sure how they accomplish this)...would the same hold true in that situation?

[Anonymous]

elbo said:

Thanks, always wondered about this. I have seen on a few threads that some people start steamVR games without letting the oculus software open (not sure how they accomplish this)...would the same hold true in that situation?

They accomplish it by setting Oculus software to "Run as Administrator".
Then Oculus Home will not automatically launch.

[Anonymous]

dburne said:

elbo said:

Thanks, always wondered about this. I have seen on a few threads that some people start steamVR games without letting the oculus software open (not sure how they accomplish this)...would the same hold true in that situation?

They accomplish it by setting Oculus software to "Run as Administrator".
Then Oculus Home will not automatically launch.

Is there any benefit to this (extra resources freed up for SteamVR games)?

[joan]

SimonSays28 said:

dburne said: They accomplish it by setting Oculus software to "Run as Administrator".
Then Oculus Home will not automatically launch.

Is there any benefit to this (extra resources freed up for SteamVR games)?

It also avoids having the Oculus Home window constantly open all day long, and also frees taskbar space. By running as admin you can have the natural behavior of having the Oculus window open only when you actually use the Rift. Otherwise even if you manually close it, any app that makes a call into the Oculus API will revive the window, like Thunderbird for some reason.