DCS VR settings guide

[Qcumber]

Is anyone interested in setting up a guide for VR settings for DCS? This could very very useful for those new to VR, those changing headsets, and for experienced VR users to share best practice. 

I know that we all have very different setups and expectations, but there are some commonalities which would apply to everyone. 

A coordinated approach would allow the experienced VR users to discuss and curate the best methods to enhance the  VR experience. At the moment there is a lot of good advice, and a lot of bad advice; most of which is communicated with good intention.

Those of us who have been using VR for a while have learned the hard way. Through trial and error, discussing issues on a multitude of threads and forums, and by watching lots of YouTube videos.

If I try to do this on my own, then it just my experience and my opinion. If we have a team of people cooperating on this then maybe we could create something that makes it a lot easier for the DCS VR experience. Best settings. Optimal performance. Coordinated bug reporting.

[Qcumber]

Bump. Anyone?

 

[Glide]

When it comes to performance testing and finding optimal settings, it's important to have a favorite testing mission where you are familiar with the visuals.  It is also very important to change only one thing at a time when you are tuning settings. 

I am happy to help.

[Qcumber]

Thanks. I have some basic missions that is use. It would be useful to have some specific scenarios with increasing detail on different maps with different modules to use as a standard. A methodological approach is important. 

[Glide]

The issue there is the amount of time it takes to test.  I have a mission that has a little bit of everything, so I just need the one for testing. 

[Glide]

Here's a dilemma for you.  Say I'm getting 80fps at 90% headset resolution (Pimax Crystal) with Quadviews.  Do I turn up the headset resolution to 140% and bring the FPS down to 40 or 50, or do I stay at high FPS with acceptable resolution?  This is with 120hz refresh rate.

Edited June 1, 2024 by Glide

[Qcumber]

1 hour ago, Glide said:

Here's a dilemma for you.  Say I'm getting 80fps at 90% headset resolution (Pimax Crystal) with Quadviews.  Do I turn up the headset resolution to 140% and bring the FPS down to 40 or 50, or do I stay at high FPS with acceptable resolution?  This is with 120hz refresh rate.

 

Can you not try both? Tweak the QVFR settings to give you a high centre res and push the periphery as low as you can tolerate. That way you can maintain high refresh. Do you need 120 Hz though? 72 fps is very fluid for me and I don't notice any difference compared to 90. My QP does not support 120Hz. 

[Glide]

i think higher refresh rate is better; it means you get a "younger" frame, sooner than a lower refresh rate. 

I tried both.  I'm running 130% resolution with 45fps.  I am really liking the higher resolution.  GPU bound with the highest resolution/refresh rate your VRAM will allow. If I had to pick a number, 20ms app GPU time in the OpenXR Toolkit FPS counter is the sweet spot for performance.

My GPU bound settings formula. 

HAGS on.  Windows Flip Mode On.  No Fullscreen in Game settings.

Nothing in the Nvidia control panel.  No Low Latency Mode.  No frame limits.  No refresh rate locks.  Nothing to get in the way of the timing between the game and the GPU.  When you are GPU bound, the GPU acts like a governor on an engine: it keeps the graphics pipeline running at a constant rate.

Nothing in the Pimax Play client except 130% resolution and 120hz refresh rate.  No Smart Smoothing.  No Dynamic Foveated Rendering.

Quadviews enabled in the PimaxXR Control Center. 

OpenXR Toolkit, I use the FPS counter a lot.  I'm using CAS 100% with TAA in Game settings.  My understanding is that Quadviews uses CAS in the center view area by default, so I am not 100% clear on the affect of using CAS with Quadviews.

In Game settings, I find Textures Medium as low as I'll go.  Terrain textures Low is a better way to keep VRAM consumption lower.  Visibility range Medium.  Shadows are Off or Flat depending on the time of day in the mission.  SS Shadows are a WIP.  You get a big VRAM and FPS boost from turning Shadows off if you can live without them.  SSLR on.  SSAO on.  These add nice visuals and load on the GPU.  No Anisotropic filtering is required at this high resolution IMHO.  Detail sliders vary depending on the map and the mission.

In summary, run the highest refresh rate of the headset, spend your "extra FPS", for me, anything above 45fps, on higher resolution, and use the game settings to keep under your VRAM limit. 

I know that 72hz/72fps is a smooth combination at times.  However, when the rdr CPU frame time jumps up above 14ms, or the GPU can't hold 14ms, you get a big desync with a sudden drop in FPS.  So, although there is no Judder with 72/72 like there is with GPU bound, the performance is more consistent and scales better across maps and missions when you are GPU bound.

These snaps are with the headset at 90% resolution getting 60fps.  A very nice balance.

Edited June 2, 2024 by Glide

[WipeUout]

On 6/2/2024 at 3:51 AM, Glide said:

i think higher refresh rate is better; it means you get a "younger" frame, sooner than a lower refresh rate.

High refresh rate is useless unless your GPU can keep up.  If not keeping up then you get stutters.   Much better to select a refresh rate you can sustain by keeping your FPS matching and still have a bit of headroom.

 

On 6/2/2024 at 3:51 AM, Glide said:

Nothing in the Pimax Play client except 130% resolution and 120hz refresh rate.  No Smart Smoothing.  No Dynamic Foveated Rendering.

Why not set refresh at 90 hz and set "lock to half frame rate", this will provide a smoother experience.  If you have a crystal and do not use the DFR, you are missing a good performance increase!

On 6/2/2024 at 3:51 AM, Glide said:

OpenXR Toolkit, I use the FPS counter a lot.  I'm using CAS 100% with TAA in Game settings.  My understanding is that Quadviews uses CAS in the center view area by default, so I am not 100% clear on the affect of using CAS with Quadviews.

If you are using sharpening in QVFR, using CAS in OXRTK is useless and just takes a bit of performance away.  Only sharpening in QVFR, not the other way around.  Also consider using QVRF to increase your resolution instead of using Pimax Play, you will get better performance and even can increase resolution higher in the focus area.

 

On 5/9/2024 at 1:36 AM, Qcumber said:

Is anyone interested in setting up a guide for VR settings for DCS?

Back to the subject, the idea is good but there are so many variations and hardware combinations, add to that all the different modules and terrains.  Neverthelss, I am willing to participate.  I already did a bit in the Pimax section :

 

8KX, 4090, i9-13900K, 64GB RAM

DCS MT

Textures High/Terrain texture High for Caucasus, Nevada and Middle-east

Textures High/Terrain Low for other maps

DLAA + DLSS Performance

Shadow low or med for Caucasus, Nevada and Middle-east, else flat

Water Med

Clouds Ultra for Caucasus, Nevada and Middle-east, else standard.

Keep off: Traffic, Heat blur, Lens flare, Secondary blur/shadows, SSAA, SSLR, SSAO, Aniso Filt., Cockpit Global Illumi., V-synch

Forest visibility 100%, detail factor at 1.0 in Caucasus, Nevada and Middle-east, else 0.1

Scenery detail at 1 in Caucasus, Nevada and Middle-east, else 0.5

Preload at max

LOD keep at 1

Gamma 1.3 (To reduce haze, must be used in conjunction with max backlit in pimax client) but for night mission, crank up.

PD =1.0

Pimax Client

Refresh 90hz

Backlit 100%

FOV Normal

Render Quality 1.0

FFR off

OpenXR

Everything at off/default

PimaxXR

Enable quadviews

Quadview

I use the following config file:

# These settings are for all headsets and applications
smoothen_focus_view_edges=0.2
sharpen_focus_view=0.0
Turbo_mode=0

[Pimax Vision 8K X]
# These settings are specific to Pimax 8K X devices.
peripheral_multiplier=0.3
focus_multiplier=1.8
horizontal_focus_section=0.20
vertical_focus_section=0.25

Process Lasso

For DCS, only use P-Cores + High priority class

Pi_server, High priority class

Additional tips and notes:

Setup two saved settings in DCS: "Setting 1" for low demand maps, "Setting 2" for high demand maps.

Acceptable AA option varies quite a lot from person to person.  For me, using DLAA/DLSS combination is great and I do not mind the small smearing.

Shadows can be improved a lot with mod "https://www.digitalcombatsimulator.com/en/files/3329503/".

Quadviews high res box (20% x 25%) may seems small but with the wide FOV of the 8KX, this will give you a resonable size with tremendous uplift in performance.

In VR, clouds are a significant performance hit and horrible at any setting except tolerable at ultra setting.  If you play a mission that has lots of clouds, you must keep ultra setting compromise elsewhere such as the "focus_multiplier" down to 1.4. in quadviews or lower HMD refresh rate.

You always have to option to lower the HMD refresh rate to 75hz or 60hz and keep same settings on any scenario but for me, 75hz and 60hz cause some flickering sometimes.

With these settings, you should get a super smooth experience with excellent clarity.  If not, then your windows/BIOS/NVCP maybe the issue.  A windows fresh install, though requiring lots of work, can cure a lot of performance problems.  If you use 4 x memory sticks on an MSI mobo, make sure your BIOS is up to date as it can cause crashes because of the stress imposed by DCS on the memory controller.  Keep overclocking low, the i9 13th gen will not be the bottleneck in your system.

Edited September 3, 2024 by WipeUout
update

[Phantom711]

@Qcumber

What you would want do do, would be quite an endeavor. Think of all the different HMD types, their respective optional add-on software which then meet all the different users with all their different hardware and personal preferences. And in that regard, who decides, what is good or bad advice?

Doing this for one family of HMDs alone (i.e. Quest) is quite a task already. And such threads with lots of discussions already exist...

 

@WipeUout

Yeah....I was gonna say the same...I had some questionmarks regarding Glide´s philosophy there as well. 

Besides that: Now I don´t have a Pimax, but a Quest Pro at the moment and I have a question regarding the "lock to half frame rate" feature of Pimax, that you mention. Does this provide a visually appealing image? Reason I am asking is, if I do this with my QP via Oculus Tray Tool or manually, objects that pass by my 3-9 line, are getting blurry. To clarify: this is with half frame rate FPS (locked) and ASW (Motion Reprojection) OFF. I am thinking, all the HMD has to do, is to show every frame twice....don´t know why it´s getting so blurry. Is this not the case with Pimax? If so, it might make a Crystal Light more interesting...even without the DFR (which I really enjoy in my QP).

Thanks in advance.

Edited June 2, 2024 by Phantom711

[Glide]

1 hour ago, WipeUout said:

High refresh rate is useless unless your GPU can keep up

I'm running 60fps at 90% headset resolution.  Super stable and smooth.

1 hour ago, WipeUout said:

Why not set refresh at 90 hz and set "lock to half frame rate"

The problem I find with locks is that you have to fiddle with them before each mission, or just set it to 30fps.

Thanks for the tip on CAS.

[Qcumber]

2 hours ago, WipeUout said:

Back to the subject, the idea is good but there are so many variations and hardware combinations, add to that all the different modules and terrains.  Neverthelss, I am willing to participate.  I already did a bit in the Pimax section :

Thanks. My aim was to create a resource for those new to VR to avoid all the pitfalls we have been through. Also a forum to discuss best practice.

[Qcumber]

1 hour ago, Phantom711 said:

What you would want do do, would be quite an endeavor. Think of all the different HMD types, their respective optional add-on software which then meet all the different users with all their different hardware and personal preferences. And in that regard, who decides, what is good or bad advice?

Doing this for one family of HMDs alone (i.e. Quest) is quite a task already.

 

There are some common principles that all HMD users would benefit from. There is too much focus on one headset over another. Thankfully with open xr things are starting to become a bit more consistent. In terms of good and bad advice, that is where we are at the moment; we are all trying to give advice subjective (with the best intentions) based on our own trial and error. That’s why i thought it would be good to have advice based upon a consensus opinion. I have a background as a research scientist and published work is based on peer review. 

[Qcumber]

1 hour ago, Phantom711 said:

And such threads with lots of discussions already exist...

Discussion, yes. But not necessarily good advice. These forums can be helpful but many comments are if the “this works for me after 3 hours experience so it must work for you/ too“ type with no logic and very little experience. the same goes for some YouTube advice. Sifting through the chaff is a chore and not something I would want to repeat. Hence the idea behind a coordinated approach based on collective experience.

[Qcumber]

3 hours ago, WipeUout said:

.  I already did a bit in the Pimax section :

I think sharing settings is good, but these will not necessarily work for everyone. I think some base principles are needed for core advice. For example, many new starters do not appreciate the requirement for super sampling for most headsets. As has been said above, using a single place for SS rather than spreading it out across various settings. How best to apply sharpening. When and how to use reprojection effectively. Using fixed and dynamic foveated rendering etc. 

By the way. Thanks for all the replies on this. 

[Phantom711]

@Qcumber

I am not saying it is a stupid idea, I am just saying it is quite an undertaking.

So basically you would want to start a thread, which you (or whoever has the authority) would update on it´s first page frequently...like it was done with the OpenComposite thread back then? Kind of? It would still be open for discussion etc...

And instead of saying what to turn on or off, one would rather explain, what it actually does and which positive or negative impact it has (benefit vs. cost).

As a baseline one should probably start with the erespective software, that conncts the HMD with the PC (i.e. WMR, Meta PC App, SteamVR) and the DCS settings. Then one could look at the optional stuff, like OXR Toolkit Companion.. possibly QVFR...

One should probably limit the scope of the thread to currently available HMDs (as new) and which are also reasonably common. And it should also not be a detailed guide on setting up your HMD.

 

[Qcumber]

How about I start some basic ideas here and this thread can help refine them. Once we have a version we are happy with we can start a new thread and ask for it to be pinned. 

[WipeUout]

21 hours ago, Phantom711 said:

I have a question regarding the "lock to half frame rate" feature of Pimax, that you mention. Does this provide a visually appealing image?

Depending on the severity of the stutter you are experiencing.  Lock Half frame rate from PimaxPlay does not work with the 8kx, I have to set 45 FPS cap in DCS settings.  It is ok but not ideal.  If you have GPU frametimes over 20ms, then it is much better than a stuttery experience at 90hz with FPS jumping up and down well below the target 90FPS.   If you can tolerate ghosting, then you are better off with smart smoothing (Pimax "reprojection" equivalent).

 

45 minutes ago, Qcumber said:

How about I start some basic ideas here

Below is a graph I did to explain what we try to achieve by tweeking settings with some explanations:

Analyzing your frame times for both CPU and GPU for a specific level of details/quality will help you see if the CPU is the bottleneck.  When setting graphics quality level, we all try to stay within an acceptable framerate for most of the time.  In order to achieve this, we set things up in order to have the CPU frametime average at a certain level that will be equal or bellow what it takes to generate the target FPS.

The GPU generate frames from data provided by your CPU.  Ideally, you need the CPU frametime to be the same or lower than the GPU frametime in order to fully use the potential of your GPU.  In this situation, you are GPU limited and it is what most of us experience in VR as it is very demanding to pump out all those pixels in such large amount.  We tweak settings for countless hours in order to be in this situation where our GPU is being used to the maximum.  At one point, you may increase the performance of your CPU by overclocking or upgrading but eventually, it is the GPU that will not keep up.  At that point, not matter how low your CPU frame time is, the average FPS will not change much.  If you experience very high peaks in your CPU frametime, then it might be helpful to consider an upgrade but It will not increase your GPU`s performance.  It might give you a more stable framerate though.

You have to analyze what is your particular situation by monitoring your CPU and GPU frametime.  OpenXR toolkit (or fpsVR if using SteamVR) is a great tool for this.  Understanding where your bottleneck is, will guide you as to where to tweek or adjust settings.  Detailed framerate datad displayed by DCS can also help understand which setting or aspect of a particular mission is consuming too much CPU resources.

[mrsylvestre]

Interesting. Until now I had the impression that it was the sum of CPU and GPU frame times that had to stay below the desired FPS to get smooth VR gameplay. For instance CPU frame time + GPU frame time < 11 milliseconds for 90 FPS or < 14 milliseconds for 72 FPS. In my understanding so far, your blue and green bars would have been stacked. On the other hand, I also do not believe that the relative size of each wouldn't matter as long as the sum is lower than the target rendering time frame. There must be some balance between the two. I am not sure what's the most accurate description of the sequence but I guess it depends how far the CPU and GPU tasks can be serialized and to which extent the CPU can work on the next simulation step while the GPU is finishing the rendering.

In any case, what we aim to avoid is the GPU sitting idle while waiting for the CPU to complete its part of the job. Hence, the GPU load factor (%use) might also be an important indicator.

[WipeUout]

On 6/11/2024 at 10:33 AM, mrsylvestre said:

I am not sure what's the most accurate description of the sequence but I guess it depends how far the CPU and GPU tasks can be serialized and to which extent the CPU can work on the next simulation step while the GPU is finishing the rendering.

DCS now has multi-threading which means CPU tasks run in parallel. There are two pipelines taken care by the CPU, simulation and graphical.   Seperating the two pipeline, i.e allocating different cores to tackle each is helping the CPU to keep frametime below the target.  If any of the two pipeline takes too much computing power, the result is a frametime too high and stutters.  It doesn't matter which pipeline is not keeping up, the result is the same: Stutters.

 

On 6/11/2024 at 10:33 AM, mrsylvestre said:

In any case, what we aim to avoid is the GPU sitting idle while waiting for the CPU to complete its part of the job. Hence, the GPU load factor (%use) might also be an important indicator.

Yes, this means that your GPU is not being used to it's full potential but low usage of the GPU can happen even if your CPU has low usage as well.  This means you can crank up your settings until you reach a frametime just below the corresponding value for your HMD refresh rate.

Personally, I use 90hz refresh rate.  I always try to keep my GPU frametime around 9 to 10ms, aiming to keep it under 11ms 99% of the time.  My CPU is not a limiting factor but I make sure only the performance cores are being used for DCS through Process Lasso.

Edited June 16, 2024 by WipeUout
Typo

[Qcumber]

Thanks for everyone's comments but I think we might be losing some focus on the original remit. I've been a bit offline recently so have not had chance to keep updated. 

My thoughts behind this is to create some principles to get people started, move through intermediate and into more advanced use.

I'll try to put together a template for what we need in basic, intermediate and advanced and we can use this for further discussion. 

[sleighzy]

@WipeUout Your custom QVF settings under the [app:DCS World] section you posted earlier may possibly no longer be being applied. You can check your QVF log file while starting DCS to double-check. DCS changed the app name to "DCS" a little while ago so it might not be finding a match for that. Check your log to confirm, and then test again using [app:DCS] as the section name and see if that produces a different result.

 

[WipeUout]

On 9/1/2024 at 5:36 AM, sleighzy said:

@WipeUout Your custom QVF settings under the [app:DCS World] section you posted earlier may possibly no longer be being applied. You can check your QVF log file while starting DCS to double-check. DCS changed the app name to "DCS" a little while ago so it might not be finding a match for that. Check your log to confirm, and then test again using [app:DCS] as the section name and see if that produces a different result.

Thanks for pointing this out, I do not use game specific setting but instead HMD specific.  My settings are updated in my post.

[sleighzy]

For folk choosing to use DLSS/DLAA see my post re: modifying the preset used, i.e. overriding the preset of C that DCS sets by default to reduce the ghosting that you can get. I've updated that post for simplified instructions to update this in your global Nvidia profile. 

 

[The_Nephilim]

Well a basic understanding and this goes for any headset. is that in VR to keep it looking smooth and silky you need to maintain the Frametime  and under for your desired HZ rate. this is what they are:

 

1. 60hz = 16.6ms

2. 72hz = 14.4ms

3. 90hz = 11.1ms

Frametime, is basically how long it takes to process the Frame by the GPU. so if you go over the frametime the affect is stutter.

So basically if you follow that guideline on any headset and your PC can maintain that Frametime or less and less is better to have some overhead the rest is all just tweaking the options in DCS to what you can and can not be able to do according to the frametime.

 

And as you see the higher the HZ rate the less time it takes so @ 90Hz you need massive FPS to achieve good frametime.. I have been following this guideline and DCS is as smoth as it is going to get within the confines of my system. now I could share my settings but rather pointless as your PC is going to be different to some degree..

 

So if you have a potato PC and are trying to run 120hz good luck with that. I bet the highest end PC's might struggle with maintaining 120+ FPS in DCS in VR.. so you just have to experiment there is no magic setting.. If you set it all high and when you hit a busy scene your Frametimes will tank and then you will get stutter I see it all the time. 

 

best bet is too find a happy medium like 4-6 points under your desired Frametime. that way if the scene gets a bit busy you have some overhead.. If you play in VR you have to compromise or suffer with stutters..

 

Now that is not withstanding current issue with the last 2 patches. it has been known for along time alot of objects especially moving ones cause stutters..

another thing could still be happening is when you do get stutters check your memory and standby memory I am gonna say it might be pretty well spiked at it's limit especially if you have terrain on HIGH..

 

the simple thing at the top is to me the biggest thing people need to understand about VR.. I am not refering to the ones who do know so don't take that personal..

 

 

Edited September 4, 2024 by The_Nephilim