A noob tip to DRASTICALLY improve overall VAM VR performance

[Voithe]

Let's be clear: I'm a noob about VR so... this may be a very well known issue but... the performance boost is too much to not ensure that everyone on the planet know that.

I discovered this "trick" thanks to MacGruber explanation of Asynchronous Spacewarp (alias Motion Smoothing). So... give a very BIG THANK YOU to him if you, like me, gain a performance boost from that.

What is Asynchronous Spacewarp or Motion Smoothing?

• By default most (or all) VR headsets try to reduce motion sickness by introducing additional interpolated images when your machine can't keep up with your headsets native refresh rate. Oculus calls this Asynchronous Spacewarp (ASW) while SteamVR uses the term Motion Smoothing (MS). While both implementations are a bit different, basically the goal for a 90Hz headset is to stablize the game framerate at 45Hz (or 30Hz), while your eyes still get the 90Hz with additional interpolated frames inbetween. This is usually a good thing, so normally, if your system can't keep stable 90fps all the time, you would want it enabled. However, for a Benchmark it makes it impossible to get useful measurements, apparent differences between machines would be very small and mostly just random noise as you can only end up with 30, 45 or 90fps. Find instructions how to turn this off below.

You can find his original post here (as part of his "Benchmark" plugin description).


So... how this works?

Since i'm using an Oculus Quest 2 on a GTX 1080 GPU, i always had the problem of FPS switching from 72 to 35, making a random slowmo effect that is very ugly. Thanks to MacGruber's explanation, i understood that the problem may be caused by this ASW thing. So... i used the Oculus Debug Tool to turn this off and, now, the FPS never switch between the two values but, instead, it drops a bit only for a second or two in particular situations!! Now i play all my scene at an average of 72 FPS! This make VAM run very smooter also in pretty everything else!! For example, now i can use the CameraWindow and even the VAM UI is more responsive.

My scenes was always pretty simple, just one Person Atom, a pixel light, some toys and environment CUA... but now... i think i can go very much further!

If you don't know, you can find the Oculus Debug Tool inside the "..\Oculus\Support\oculus-diagnostics\" folder. You have to use it when your headset is on and... you also have to change the setting everytime you turn the headset on after switch off (long press on power button).


I hope this can be of some help for other noobs like me... and... let me know if it is!

 

[MacGruber]

Some quick notes on this:

1. "Asynchronous Spacewarp" / "Motion Smoothing" are there for a reason. Both companies should have clever people working for them, right? It's supposed to fight motion sickness, in most situations it should improve things because it increases your effective framerate, it just does not show in the FPS counter of your game, because its done by the Oculus software.
2. At least for Oculus ASW, this needs to be disabled after the Oculus software was started, because its enabling ASW on startup.
3. Attached to the Benchmark plugin resource is a ZIP with two little scripts inside. Those enable or disable Oculus ASW for you. Much easier than fiddling with the Oculus Debug Tool which sometimes doesn't seem to apply settings and you could break things when playing with the other settings there.

 

[Case]

Small nitpick: Only the Quest 2 has ASW - not the Quest 1! (ASW runs on the Q2's upgraded internal chip, not on your PC)

My apologies, I confused ASW and SSW (see below)

 

[Voithe]

Thanks for the pro-notes!

For me ASW is bad because of the random slowmo effect. Before that, i tried to compensate this by changing Physics Rate and Pysics Update Cap but... it was bad since it caused a loss of smoothness.

Note that i don't suffer from motion sickness at all and i mostly play seated.

 

[Case]

Thanks for the pro-notes!

For me ASW is bad because of the random slowmo effect. Before that, i tried to compensate this by changing Physics Rate and Pysics Update Cap but... it was bad since it caused a loss of smoothness.

Note that i don't suffer from motion sickness at all and i mostly play seated.

Do you use VirtualDesktop? VD got ASW integration SSW a few months back ... I don't have a Quest 2, so I can't check for myself - but back when this was announced, folk on the VD discord got pretty exited, because ASW SSW can drastically improve quality of streamed imagery, with little performance cost on the PC.

(As far as I understood, the trick with ASW SSW is that it helps improve bottlenecks due to bandwidth limitations implcit in streaming content from the PC to your goggles.)

Mentioning this bcs (this is total guesswork!) - the problems you experienced don't necessarily have to be the fault of either VaM, or ASW. Could be SteamVR or some driver settings or whatever. Maybe there's an easy workaround, and it just so happens that something in the pipeline from VaM to your goggles isn't yet optimized for ASW.

And the ppl at VirtualDesktop are usually pretty clued in about all things Occulus ...

TL;DR - Usually, ASW SSW isn't seen as a nuissance ...


Edit: Sorry, confused Occulus' ASW with VirtualDesktop's SSW. The two are often compared to another, but are not the same - SSW does indeed only work on the Q2.

 

[Voithe]

No... sorry. ASW have nothing to do with the stream bandwidth. If understood well, it is a "feature" that make the GPU (or the headset... i don't know well how this works) "predict" the next freame instead of calculating it (sure someone more expert than me can explain this better).

That said... my Quest 2 is connected to my PC by the original Oculus Link cable (optical fiber). No bandwidth troubles at all.

Thanks for the reply anyway...

Edit: And even SteamVR have nothing to do with that since i don't use it.

 

[Case]

No... sorry. ASW have nothing to do with the stream bandwidth. If understood well, it is a "feature" that make the GPU (or the headset... i don't know well how this works) "predict" the next freame instead of calculating it (sure someone more expert than me can explain this better).

Urgh! You're right - I confused ASW with the custom SSW Guy Godin wrote for VirtualDesktop (

https://www.reddit.com/r/OculusQuest/comments/nwsh8c

).

Sorry!

 

[Jiraiya]

The main good thing about SSW on VD is that it runs in the headset so the load is removed from the PC. Obviously interpreted frames are not as good as native frame rate but it essentially doubles your framerate for free by making use of a second GPU.
Virtual Desktop is now starting to work on the FidelityFX stuff I went wild about a while back, they have already added the sharpening (again, using the Quest2 headset GPU) to improve picture quality. If they can get the resolution upscaling integrated in the headset GPU as well it should give an amazing performance boost compared to a single GPU rendering "the best it can".

 

[Voithe]

Whoa... if this is true, i think it's time for me to try this Virtual Desktop. Thanks for the info @Jiraiya !

 

[Jiraiya]

I did a test of VD verses Airlink and it outperformed Airlink on my system by a tiny fraction. When you add in SSW and Sharpening, it's much nicer. I can't wait to see if they get the upscaling working well. It runs down the quest2 battery quicker obviously but I am very happy with the performance improvements compared to struggling with SteamVR.

 

[jumpy2222]

Since i'm using an Oculus Quest 2 on a GTX 1080 GPU, i always had the problem of FPS switching from 72 to 35, making a random slowmo effect that is very ugly. Thanks to MacGruber's explanation, i understood that the problem may be caused by this ASW thing. So... i used the Oculus Debug Tool to turn this off and, now, the FPS never switch between the two values but, instead, it drops a bit only for a second or two in particular situations!! Now i play all my scene at an average of 72 FPS!

You get 72 FPS with a 1080 and Quest 2? ... I have a 3080ti and a Quest 2 and barely get above 30.

 

[TToby]

You get 72 FPS with a 1080 and Quest 2? ... I have a 3080ti and a Quest 2 and barely get above 30.

This strongly depends on the scene, the ammount of figures, the hair and clothes that are being used and on how many light sources the scene is using, aso.
We often had this discussions and you almost never could compare FFP from one user to another. Because of this, MacGruber has made a standardized benchmark scene, and many people had posted their results in the Benchmark-thread(s). If your results are not too much different to other users, everything should be OK.

 

[jumpy2222]

This strongly depends on the scene, the ammount of figures, the hair and clothes that are being used and on how many light sources the scene is using, aso.
We often had this discussions and you almost never could compare FFP from one user to another. Because of this, MacGruber has made a standardized benchmark scene, and many people had posted their results in the Benchmark-thread(s). If your results are not too much different to other users, everything should be OK.

Ah, yes, 61 FPS from the standardised benchmark tool. Ryzen 9, 3080ti.