Performance in VR and FPS question

OK... all of this now makes perfect sense and I will follow the good advice provided. One quick follow up question. I have 3 ways to set SS.

1) SteamVR Global application default setting (which in my case as I noted earlier is 200%)

2) SteamVR per application setting which is a multiplier on top of the default

3) In-game SS (in the case of DCS using PD)

imaken thanks for the math and overview. You seemed to lean towards using DCS PD. Is there any specific performance or other reason? I was planing to keep my Global at the default of 200% for all other general games. So in order to reduce SS for DCS I would have to set my SteamVR DCS application specific setting to 50% and then set DCS PD to 1.8 or 2.0. Or I could just to leave the Global SteamVR setting at 200% and then set PD in DCS to 1.0. Is there a performance or other reason to be using the DCS PD as the main determinant for SS? Thanks

Yeah but that 200% is probably fine for the vast majority of VR games. DCS needs some serious fixing with regard to VR.

Not sure about that. Try it in Fallout 4 VR. Anyway, almost all VR games have their own in built SS setting, so having a global default that is 4x native seems way over the top.

Yeah, I'm not seeing huge increases in "quality"/clarity from pd1.0 to 1.2 to 1.4 ish which is the upper limit of what I can run and still pull 45 frames. MSAAx2 seems to help mainly be eliminating shimmer/artifacts. Recently got the shader mod, which freed up enough resources to go from PD1.2 to 1.3 and turn MSAAx2 on.

You should see quite a significant difference between 1.0 and 1.4.

The shader mod has too many poor visual compromises and drawbacks for me.

OK... all of this now makes perfect sense and I will follow the good advice provided. One quick follow up question. I have 3 ways to set SS.

1) SteamVR Global application default setting (which in my case as I noted earlier is 200%)

2) SteamVR per application setting which is a multiplier on top of the default

3) In-game SS (in the case of DCS using PD)

 

imaken thanks for the math and overview. You seemed to lean towards using DCS PD. Is there any specific performance or other reason? I was planing to keep my Global at the default of 200% for all other general games. So in order to reduce SS for DCS I would have to set my SteamVR DCS application specific setting to 50% and then set DCS PD to 1.8 or 2.0. Or I could just to leave the Global SteamVR setting at 200% and then set PD in DCS to 1.0. Is there a performance or other reason to be using the DCS PD as the main determinant for SS? Thanks

I didn't mean to lean towards PD, but now that you've said that, I'm going to try out the equivalent combinations and see if there is a difference.

Here are a few calcs of total pixels per eye based on the Vive Pro with slight rounding of the SteamVR figures to make it easy:

PD 1.0 and SteamVR SS 50% - 2.3m

1.5 and 100% - 5.2m

2.0 and 200% - 9.2m

So, it makes sense to compare the combinations 1) SS 50% and PD 2.0 with 2) SS 200% and PD 1.0.

I'll give that a go now!

Not sure about that. Try it in Fallout 4 VR. Anyway, almost all VR games have their own in built SS setting, so having a global default that is 4x native seems way over the top.

 

 

You should see quite a significant difference between 1.0 and 1.4.

The shader mod has too many poor visual compromises and drawbacks for me.

I'll check it between those 2 values. I've been running 1.2 as a standard for a while now as it was the best I could do on my system, and with the shader mod I can probably goto 1.4 on the "good" planes, I'm not seeing a ton of difference between 1.2 and 1.4 is more accurate since I just did that comparison this morning 1.4 might a tiny bit more "clear".

The only other VR game I'm using regularly is IL2 which I can run at 120% on steam, and its "high" gfx settings. In general it performs better and looks better than DCS graphically/proc speaking so I figure its a bit more optimized. But no clicky pits and arcade FM's aren't great either.

I didn't mean to lean towards PD, but now that you've said that, I'm going to try out the equivalent combinations and see if there is a difference.

Here are a few calcs of total pixels per eye based on the Vive Pro with slight rounding of the SteamVR figures to make it easy:

PD 1.0 and SteamVR SS 50% - 2.3m

1.5 and 100% - 5.2m

2.0 and 200% - 9.2m

So, it makes sense to compare the combinations 1) SS 50% and PD 2.0 with 2) SS 200% and PD 1.0.

I'll give that a go now!

OK, so I've tried various combinations resulting in the same number of pixels, and I cannot see any difference between biasing towards PD or SteamVR. I guess that is kind of reassuring.

Personally, I am sticking with 1.5 PD and a SteamVR SS of 100%.

That gives me - with pretty high DCS settings - 45fps most of the time, and only dropping to 30fps at low altitude in quite dense terrain.

Just a heads up today's update fixed the huge aliasing issue and some performance has returned, now about improving VR in game performance and map performance. :thumbup:

Just a heads up today's update fixed the huge aliasing issue and some performance has returned, now about improving VR in game performance and map performance. :thumbup:

What ‘huge aliasing issue’?

What ‘huge aliasing issue’?

Well just an issue I experienced with Rift VR with the first "2.5.4" update seems resolved now so far. Cheers. :thumbup:

You're more than welcome, but I trust that this was not new info for you =)

I just checked out SteamVR on my CV1 and you are absolutely right. Haven't used SteamVR for some months now so I was completely unaware of this change.

 

It seems that after the update, the old 100% has become the new 50%.. I don't understand why they would do this though... It makes no sense to me; why label something 50% ("per eye") when it is in fact 100% (The native reso)?

 

Thank you for setting it straight mate! I will be sure to modify my post and add a disclaimer.

 

Silly Gaben doing silly stuff instead of giving us HL3... :P

 

Cheers! :smartass:

 

IT--

The rendered image needs to be a higher resolution than the displays because of the effect of distorting it to correspond with the headset's lenses. Roughly, the number of overall pixels rendered needs to be double the headset's resolution. Presumably that's where the percentages come from.

I keep finding reasons to post a link to the same pdf, but it's all explained here. Page 14 onwards.

The rendered image needs to be a higher resolution than the displays because of the effect of distorting it to correspond with the headset's lenses. Roughly, the number of overall pixels rendered needs to be double the headset's resolution. Presumably that's where the percentages come from.

 

I keep finding reasons to post a link to the same pdf, but it's all explained here. Page 14 onwards.

Thats a good read. You really gotta wonder if DCS has tried any of those VR optimizations they mention or if those are the "promised" improvements even though that paper is from 2016.