FrameTime VR and DCS world 2.5.5

[The_Nephilim]

Hey Guys,

 

 

I been reading performance enhance threads here since forever.. I have found 1 thing too most of those posts they did not apply to me..

 

 

Mostly because the gear used was far superior to my own gear.. LOL!!

 

 

Now I have been rechecking some VR threads to try and tame the FPS well what I have discovered since I tried VR is the FPS really are not there in DCS world anyway..

 

 

I have an Odyssey Plus and used it for about 2 months now. I have found out even though I disabled Motion Reprojection the most FPS I seem to be abe to achieve is about 40-50 FPS even in MP but up high sometime get in the 60's

 

Now,I rediscovered what is a great deal important too is FrameTime.. now I would imagineby now most have heard of this and if you have not well basically it is the amount of time it takes too draw 1 frame and lower is better..

 

 

You can find all the specifics about it around the web I'll spare you the boring details.. but I found out even thos I could achieve 45 FPS with Graphics maxed is that I would have a Very High Frametime thanks to my newly aquired fpsVR frame counter.. and it would not be too smooth in gameplay or fluidity..

 

 

So I spent the last few hours figuring out the best Frametime for me, I wanted to achieve under 14MS but unless you go LOW on Everything this is not possible in DCS World so between 16-24s was the goal.

 

 

I achieved that and get around 18-21MS frametime with the following settings screenshots attached..

 

 

here is my PC Gaming Rig:

 

 

1. Intel i5 7600K @ 4.9GHZ - AVX at Zero

2. MSI Z270 SLI Motherboard latest manufacturer updates..

3. Asus 1080GTX OC Factory.. 1736mhz Boost. 430.86 drivers..

4. SoundBlaster Z Soundcard latest drivers..

5. Thrustmaster Cougar.

6. Thrustmaster MFD's.

7. Samsung Odyssey Plus at 100% resolution in VR..

 

 

 

 

Now I toiled with this for several hours over 3 days.. Hopefully it might help you or give some ideas at the least.. I was hoping better for the VR Enhancements but it looks like I was largely unaffected with ED's release of VR Enhancements this round..

 

 

I also reported to ED with their thread to test the T-51 in Tiblisi from what I seen most really didn't fair much better then me but some did..

 

 

 

 

I just wanted to make this post showing the other side of the coin in Framtime and importance for it in VR especially..

 

 

Heck on my 1080P monitor I maxed the settings and was getting like 150FPS just weird in VR it kills the FPS and Frametime..

 

 

Hopefully we can get some better enahncements for VR in DCS in the coming weeks.. I look forward to it but right now I found a good Blalance..

[DeltaMike]

Good job.

 

I'd look at the pixel density, it's kind of a "U" shaped curve. As you increase it up to a point it looks good, after that point it gets hard to spot things and text gets blurry. PD is brutally expensive in terms of the load on your GPU, dial that back a little and you can get your trees back maybe.

 

Also you should be able to set water and anisotrophic filering to high, those are almost free

[The_Nephilim]

Well thing is with PD I really don't see much difference over 1.5.. I can try 1.3 or 1.2 and maybe up the trees a bit..

 

 

I could have sworn when I put the water on High I had a really bad FrameTime?? I will experiment more with the water setting.. As for the AF I had that on x8 I must have forgotten to put it back on for the screenshot..

 

 

But AF is @ x8, there really is not much difference with it at x8 vs x16 but I will check and see what the cost was for each setting..

 

 

thing is I found out I can go higher then this but then the FrameTime starts to increase really a lot.. I am unsure what the max FramTime should be but I did notice stuttering a bit with the higher Frametime..

 

 

So I kept it as close to 8-12ms as I could..

[fearlessfrog]

So frame timing is just sort of another way of expressing performance. If your headset is 90 Hz then that's 90 frames per second, so that's a budget of 11.1 milliseconds to render a frame (1000 / 90 = 11.1r) so you don't see a disconnect to where you are looking and DCS is drawing.

 

DCS on more or less any system struggles to work in a budget of 11ms, as it's either the GPU struggling doing something expensive like MSAA or the CPU main thread being blocked with lots of draw calls.

 

As you've seen, it's more realistic to try to aim for some sort of reprojection, where the budget will be 22.2r ms. WMR has an 'always on' rotational reprojection for an app that doesn't reach 90 Hz. Rotational reprojection works well, in that you can move your head around the cockpit, see 90 fps but only be rendering 45 fps. The downside is that you get 'ghosting' where if you look sideways, or at something with an aspect ratio not around the X-axis of your head, then the artifact will 'leap' between frames, i.e. you see 'juddery trees' and the like.

 

The optional opt-in 'motion reprojection' of WMR [1] helps with this, and is like Oculus's ASW and SteamVR's reprojection. For this to work well you need about 60 fps or a frame timing of about 16 to 18 ms. If you can tune for that then the motion reprojection can work well. If this is enabled you'll only see 45 or 90 on your FPS though, so worth tuning the framerate without it.

 

As for DCS PD vs SteamVR SuperSampling (that WMR uses for scaling), I've personally found that a DCS PD of 1.0 and then a SteamVR SS of 212% works well on the Odyssey. Obviously this is not a hard and fast rule for everyone, as clarity and all the various combination of settings is just a personal preference. It is worth a try if you haven't tried that. There is an issue on Win10 v1903 that sort of impacts this, but that will hopefully be fixed soon. [2]

 

[1] https://docs.microsoft.com/en-us/windows/mixed-reality/enthusiast-guide/using-steamvr-with-windows-mixed-reality#enabling-motion-reprojection-for-steamvr-apps

 

[2] https://steamcommunity.com/app/719950/discussions/0/1644292361960505688/

[The_Nephilim]

Well I did get it down to 9ms with all options as low as they could go and in the t-51 flying over Tiblisi….

 

 

Thing was most of my settings where maxed out but the FrameTime was terrible causing stutters in the game but I still had 45-50FPS.. it was not very smooth most times so I thought if I could get the framtime down it would smooth out which it did..

 

 

So while you maybe getting good FPS Frametime tells another story..

 

 

S

[Thunderchief2000]

Well I did get it down to 9ms with all options as low as they could go and in the t-51 flying over Tiblisi….

 

 

Thing was most of my settings where maxed out but the FrameTime was terrible causing stutters in the game but I still had 45-50FPS.. it was not very smooth most times so I thought if I could get the framtime down it would smooth out which it did..

 

 

So while you maybe getting good FPS Frametime tells another story..

 

 

S

 

 

Frame time IS FPS, its is just another way of expressing it. however because most if not all headsets will lock fps at set points (90 - 45 - 30) it can be hard to understand the relationship.

 

 

I suspect what you were seeing was the difference between an averaged fps counter which does not show the spikes and drops as much. where as the frame time counter, at least in SteamVR, is as close as possible to realtime.

 

 

As stated before 11.1 ms is the maximum the frametime can be before the headset will drop the locked fps from 90 to 45. In reality it would have to be lower, (probably 8-9ms) especially in DCS which does spike quite a bit from my experience, to consistently stay locked to 90

 

 

Once you drop below 90 and the fps is locked to 45 there is nothing to be gained by keeping your frametime close to, but not below 11.1ms. You could go all the way up to 22.2ms an get exactly the same fps performance (well actually as before, to account for spikes you need to allow 10% or so, I use 19ms)

 

 

Obviously you need to benchmark a scene that would represent the highest load your system will generally see. I use a low flight over Caen on the Normandy map with a few AI in the area, seems to work quite well.

 

 

This way to can maximise your visual fidelity when accepting that you will never reach 90FPS

 

 

Cheers.

[toutenglisse]

The thing that make frametime superior is that it always show headroom (CPU and GPU).

 

Due to limitations (asw / full 80 or 90 fps (or120)), fps don't always show headroom - you have to correlate with GPU/CPU usage wich gives a not that clear estimation.

[Svsmokey]

Good point !

[The_Nephilim]

Well it is the inverse but it is better to know the frametime vs the Frames per second..

Edited June 26, 2019 by The_Nephilim

[etherbattx]

Well it is the inverse but it is better to know the frametime vs the Frames per second..

 

kind of. if you are talking to a geek.

 

but most of us only understand FPS.

[M1Combat]

Then read a few posts ago and you'll understand frame time :)

[VitS]

As someone else mentioned problem is spikes. You can spend hours tuning your settings but when you fly to some place with lots of geometry and all of the sudden you sitting at 30 fps

[The_Nephilim]

As someone else mentioned problem is spikes. You can spend hours tuning your settings but when you fly to some place with lots of geometry and all of the sudden you sitting at 30 fps

 

 

 

I have yet to see that happen. where is this place you speak of?? I would like to visit there myself..

 

 

I have spent a few hours into this and I rarely go below 40 it is mostly at 45 averages 47.5..

 

 

You just can Not have the eye candy cranked and think it will always be stable FPS or Frametimes..

 

 

I just was in last night fine tuning a thing or two and noticed I bumped up my PD and that was a major bog of the system.. I went back down to 1.0 and it was fine again..

 

 

This sim may be poorly optimized or whatnot but Most of the times the guys with the Bad FPS are maxing everything and PD at 1.8-2.0 just will not happen..

 

 

you have to compromise and PD is a Biggie.. I really think it is funny but maybe we will get better optimisations in the future for VR that are more rounded for all users and not just a few see improvements..