Why is DCS in VR with 12th & 13th gen CPU, DDR5, and 4090 so applalingly slow?

[DmitriKozlowsky]

Why is DCS in VR with 12th gen CPU, DDR5, and 4090 so applalingly slow?

Getting 40-60 FPS with VR on such system is not just a bug. It is an appalling fail! A fail! Not a WIP, not it will get better. It is a fail.  It is completely unacceptable  low level of performance. Sliding various options up and down, turning OFF anti-aliasing, does not improve performance by more then 5-7 FPS. With a VR set, that system cost exceeds $6500. DCS can only pump out measly 60FPS on a good day with empty sky.  Where is the bottleneck? Is it the VR set? I don't understand how this level of performance be viewed as acceptable, or be allowed to go to market. 

Here is what should be acceptable for VR and its simple. VR set refresh rate X 2. That is FPS that DCS needs to deliver for VR to be acceptable. If the DCS is unable to deliver this on a system, then DCS cannot be used for VR on that rig, with those DCS settings. DCS with 3195 pixel VR with 75hz refresh rate has to deliver constant unvarying min of 144FPS without drops, tears, or stutters. If DCS cannot do it, then it should not be used with VR on that system.

[St4rgun]

DCS is much older than the current PC VR technology therefore the ancient graphics engine holds back the performance heavily on cutting edge hardware.

As I understand right now (and someone please correct me if I'm wrong) the engine renders the stereo frame independently for each eye. so no optimization is in place to render the exact same scene from a slightly different eye position for L and R eyes. This combined with the high resolution of the modern HMDs is a performance disaster.

We all hope, that in the near future multicore update will finish the internal beta testing and eventually crawl to OB and after that Vulkan implementation could change this resource hog we have right now. What can be done now is some tweakig with either the DCS settings, using OpenXR with OpenXR ToolKit (ie. fixed foveated rendering) and applying other tricks to have at least stable 45 fps (!!!) on a rig similar of mine at native HMD resolution. This is a shame as the G2 native refresh rate is 90 Hz, but it is at least usable.

That's why I really like the new FPS counter and details window: if it will work correctly it can help finding the bottlenecks.

[zildac]

With similar specs to you I had very good performance (albeit still choked by AI in some scenarios). 2.8 put paid to that   Ironically the new FPS counter now makes it even easier to see how much worse the performce is LOL

[DmitriKozlowsky]

2 hours ago, zildac said:

With similar specs to you I had very good performance (albeit still choked by AI in some scenarios). 2.8 put paid to that   Ironically the new FPS counter now makes it even easier to see how much worse the performce is LOL

Please,  if possible, post your rig specs, VR set native specs, DCS options page , and average FPS with SU-25T and KA-50 BS2.

If your VR  FPS is not in tripple digits , and substantially less then VR refresh rate X2, then DCS VR performance on your rig is poor. VR is not same as panels. There should not be FPS rate dance. It must be constant. 

45 FPS is not usable,

60 FPS is poor performance

90 FPS low but marginably acceptable 

120 FPS acceptable for VR set with 60 refresh rate.

144 FPS is good performance for VR sets with 75 refresh rate

180 FPS excellent performance with high end VR set

Once again there should not be average FPS in VR in given mission. FPS needs to be constant from start of mission to end.

 

[St4rgun]

I understand your argument, but calculating a x2 multiplier as a minimum factor for refresh rate is a bit steep IMHO.

I would be really happy if my VR headset can provide a rock solid 90 fps at native resolution by having DCS stable 100 fps all the time, I would not require bigger headroom.

[zildac]

1 hour ago, DmitriKozlowsky said:

Please,  if possible, post your rig specs, VR set native specs, DCS options page , and average FPS with SU-25T and KA-50 BS2.

If your VR  FPS is not in tripple digits , and substantially less then VR refresh rate X2, then DCS VR performance on your rig is poor. VR is not same as panels. There should not be FPS rate dance. It must be constant. 

45 FPS is not usable,

60 FPS is poor performance

90 FPS low but marginably acceptable 

120 FPS acceptable for VR set with 60 refresh rate.

144 FPS is good performance for VR sets with 75 refresh rate

180 FPS excellent performance with high end VR set

Once again there should not be average FPS in VR in given mission. FPS needs to be constant from start of mission to end.

 

Specs are in my sig. Sorry, but show me ANY rig that can run a Varjo Aero at 90FPS unless the settings are potato mode! My point was I had 86 FPS in VR with my Aero at 37PPD....with 2.8 I get 60FPS WITH THE EXACT SAME SETTINGS. And to say 45FPS is not useable is nonsense. There are plenty of G2 owners running at 45FPS happily, as was I when I owned one.

Edited October 30, 2022 by zildac

[DmitriKozlowsky]

4 minutes ago, zildac said:

Specs are in my sig. Sorry, but show me ANY rig that can run a Varjo Aero at 90FPS unless the settings are potato mode! My point was I had 86 FPS in VR with my Aero at 37PPD....with 2.8 I get 60FPS WITH THE EXACT SAME SETTINGS. And to say 45FPS is not useable is nonsense. There are plenty of G2 owners running at 45FPS happily, as was I when I owned one.

 

I am unable! EVERY DCS VR rig I have exprienced had same performance issues. Which is to say insufficient performance. 

[zildac]

4 minutes ago, DmitriKozlowsky said:

I am unable! EVERY DCS VR rig I have exprienced had same performance issues. Which is to say insufficient performance. 

45FPS was achievable on my G2 with mostly high settings and 2xMSAA however there were of course drops when AI was heavy etc.

[w00k]

I completely agree. The engine age, and the lack of optimization, coupled with the focus on products and feature enhancements is a pretty serious issue. I do understand that ED need to develop cost based product updates to generate an income, but at this stage the apparent lack of focus on the engine is rendering the game unplayable in VR. I really do think that they need to set aside a pool of resources to focus on updating the core engine.

[DmitriKozlowsky]

Yes. I want to reiterate. I am a big fan of DCS. I love many aspects of it. ED has done a fantastic job. BUT NOT IN VR!

On a bleeding edge ultra high end gaming PC with Varjo (my favorite) VR , DCS cannot claw its way higher then 60 FPS, and often delivers 45-50 something FPS. What hope is there for plain high end or everyday Joe 6-pack gaming PC with affordable VR. NONE! 

I'd rather have three curved 1440 panels with TrackIR. Or those insane ultra hyper wide gaming screens , with TrackIR. I visited Micro Center , and they just got bendable curved panels. Pricy , but make much more sense then VR. Center panel would have moderate curvature and two side panels with more pronounced curve. Whatever happened to stereo glasses? 

With 3080Ti or 4090 and sensible DCS settings, 144 to 180 FPS play can be delivered. 

[freehand]

I love vr in dcs but dcs is not advertised as a VR game me thinks  I could be wrong but more of an after thought.

[trevoC]

I'm running a 5900X Oc'd 20% with a 3090 and I can play VR just fine with high/extreme settings. What has enabled this is openXR with FFR.

My test scenario is Huey on Marianas map (which is one of the worst offenders for my setup). I get about 43 fps in this setup.

In comparison, an su-25 on Cauc. would give me 65 at the low end (may dip there) and up to 90 on the high end... usually the mid to high 70's fps. This is the story for most of the jets on this map.

I disagree in regards to what you find "usable" fps. If you are expecting 180 fps as your bar, go 2d and come back in 5 years. Thats your choice.

I find dips below 30 to be noticeable enough to be uncomfortable to play, but anything high 30's low 40's is playable. I flew the entire paradise lost campaign on marianas at about 45-60 fps just fine.

If you find 60 fps unplayable I'm guessing you have some other setting that is making it this way. I found that all motion smoothing type settings make my experience horrible and are turned off. YMMV, obviously.

Not sure what game you are playing that is delivering 180 fps in VR that is anything close to DCS... maybe some light sabre slashing fruit game.

[Rosly]

22 hours ago, DmitriKozlowsky said:

Why is DCS in VR with 12th gen CPU, DDR5, and 4090 so applalingly slow?

Getting 40-60 FPS with VR on such system is not just a bug. It is an appalling fail! A fail! Not a WIP, not it will get better. It is a fail.  It is completely unacceptable  low level of performance. Sliding various options up and down, turning OFF anti-aliasing, does not improve performance by more then 5-7 FPS. With a VR set, that system cost exceeds $6500. DCS can only pump out measly 60FPS on a good day with empty sky.  Where is the bottleneck? Is it the VR set? I don't understand how this level of performance be viewed as acceptable, or be allowed to go to market. 

Here is what should be acceptable for VR and its simple. VR set refresh rate X 2. That is FPS that DCS needs to deliver for VR to be acceptable. If the DCS is unable to deliver this on a system, then DCS cannot be used for VR on that rig, with those DCS settings. DCS with 3195 pixel VR with 75hz refresh rate has to deliver constant unvarying min of 144FPS without drops, tears, or stutters. If DCS cannot do it, then it should not be used with VR on that system.

Can you share vid with fpsVR overlay?

DCS have many issues but it might also be you have problem in your setup.

Do you use Win 11 (Otherwise scheduler will mess up with your 13900 e-cores)?
Do you updated BIOS (otherwise you might have issues with boost clocks ).

[zildac]

Can you share vid with fpsVR overlay?
DCS have many issues but it might also be you have problem in your setup.
Do you use Win 11 (Otherwise scheduler will mess up with your 13900 e-cores)?
Do you updated BIOS (otherwise you might have issues with boost clocks ).

2.8 is broken.... Simple

[St4rgun]

9 hours ago, zildac said:

10 hours ago, Rosly said:

Can you share vid with fpsVR overlay?
DCS have many issues but it might also be you have problem in your setup.
Do you use Win 11 (Otherwise scheduler will mess up with your 13900 e-cores)?
Do you updated BIOS (otherwise you might have issues with boost clocks ).

2.8 is broken.... Simple

As I said also in the patch notes thread, for me the new frametime graph of the fps counter can be very spikey normally during a mission but it became super smooth if I start an instant mission with ANY airplane in cold and dark state. Which equals super smooth visuals in VR with the same details as when the simulation runs. It means that the GPU can render the extreme quality in VR without problem, but when the simulation of my own plane starts the CPU is so highly capped on the max. 2 cores that the rendering heavily suffers.

Now I can visualize why the devs are working so hard on the multicore development. Actually I became extremely hyped on the hopefully incoming MC news as it seems that switching on the idle cores in my CPU will literally make WONDERS on the rendering smoothness also!

Combine this with a future finalized Vulkan API I'm sure that VR will be much better. I really hope that performance wise the current 2.8 implementation is the bottom of the pit.

@BIGNEWYCan you say a word about MC and/or Vulkan current status? As earlier said MC is in closed beta testing some time before. Will MC mean 2.9 and after that Vulkan 3.0? Is it possible that these two steps wont need another years?

Edited October 31, 2022 by St4rgun

[BIGNEWY]

10 minutes ago, St4rgun said:

@BIGNEWYCan you say a word about MC and/or Vulkan current status? As earlier said MC is in closed beta testing some time before. Will MC mean 2.9 and after that Vulkan 3.0? Is it possible that these two steps wont need another years?

Multi threading is in testing and we will share news as soon as we are ready, vulkan is in progress and will come after multithreading, again I have no timescale to share currently. 

thanks

On 10/29/2022 at 11:55 PM, DmitriKozlowsky said:

Why is DCS in VR with 12th gen CPU, DDR5, and 4090 so applalingly slow?

Getting 40-60 FPS with VR on such system is not just a bug. It is an appalling fail! A fail! Not a WIP, not it will get better. It is a fail.  It is completely unacceptable  low level of performance. Sliding various options up and down, turning OFF anti-aliasing, does not improve performance by more then 5-7 FPS. With a VR set, that system cost exceeds $6500. DCS can only pump out measly 60FPS on a good day with empty sky.  Where is the bottleneck? Is it the VR set? I don't understand how this level of performance be viewed as acceptable, or be allowed to go to market. 

Here is what should be acceptable for VR and its simple. VR set refresh rate X 2. That is FPS that DCS needs to deliver for VR to be acceptable. If the DCS is unable to deliver this on a system, then DCS cannot be used for VR on that rig, with those DCS settings. DCS with 3195 pixel VR with 75hz refresh rate has to deliver constant unvarying min of 144FPS without drops, tears, or stutters. If DCS cannot do it, then it should not be used with VR on that system.

If you are getting 40 - 60 in VR in DCS you are doing well, and should have a good experience. I target 45 minimum with my settings, that is where I am happy, but I see 45 - 90 depending how busy the mission is and where I am in the sky.

You have to remember that DCS was here years before VR, it was not built from the ground up for VR, it is a complex simulator. 

What we have now is great considering, hopefully multi threading will help in the near future. 

[zildac]

@BIGNEWY I'll add this here again but a drop from 86FPS in a given scenario under 2.7 to 61FPS in 2.8 is not normal, something must be wrong here surely?

[BIGNEWY]

11 minutes ago, zildac said:

@BIGNEWY I'll add this here again but a drop from 86FPS in a given scenario under 2.7 to 61FPS in 2.8 is not normal, something must be wrong here surely?

We have a shadow issue that should be fixed in the next patch, and we are looking into other reports also. Just to note we are getting reports of FPS increase as well as FPS drops. 

[zildac]

11 minutes ago, BIGNEWY said:

We have a shadow issue that should be fixed in the next patch, and we are looking into other reports also. Just to note we are getting reports of FPS increase as well as FPS drops. 

Thanks for the prompt response. Yes, I appreciate that others seem to have had an increase which is even more confusing frankly. I am specifically talking about VR here so we probably need to work out what the difference is with those seeing an increase in VR performance. My drop is easily reproducible and happens whether I'm using native OpenVR via SVR or OpenComposite.

[BIGNEWY]

Personally I had a slight increase but not massive. 

[St4rgun]

@BIGNEWYIf you are already here, a word about the clouds: hopefully "some optimizations" made in 2.8 already to have smoother experience for the clouds in VR, which is true at least for me. But is it normal that while the close clouds are pretty nice even on Standard the others on the horizon and far away are very low resolution and have heavy aliasing despite of MSAA 2x and nvidia transparent AA 8x? Will be there some kind of development on eliminating ALL of those aliasing artifacts?

[BIGNEWY]

Just now, St4rgun said:

@BIGNEWYIf you are already here, a word about the clouds: hopefully "some optimizations" made in 2.8 already to have smoother experience for the clouds in VR, which is true at least for me. But is it normal that while the close clouds are pretty nice even on Standard the others on the horizon and far away are very low resolution and have heavy aliasing despite of MSAA 2x and nvidia transparent AA 8x? Will be there some kind of development on eliminating ALL of those aliasing artifacts?

its best to make a new thread, keep this one for FPS discussion. 

but we are looking at feedback  currently and any issues being reported.

[KoN]

DCS is an old engine 1990s . We are all waiting for Vulkan . And i hope the spotting issues get fixed . 

[Swson]

After many trials and parameters' trimming I finally got a 35 to 45/60 FPS in quite all modules and terrains with my G2. That is fully acceptable. However it is far from results obtained with MSFS2020 and a google map terrain much more defined. Worst results are with AH-64 and moreover DCS is unplayable with DCS liberation dynamic campaign where 8 to max 17FPS are obtained in the lightest scenario. Management of many object is probably the reason because complex mission with briefing room are playable correctly... I agree that the graphic engine is outdated and I'm very surprised that the CPU is not really used (max 20%) even in single thread compared to the GPU; I'm using a AORUS 490 chipset with a 10700K I7 and a AMD 6900XT slightly overclocked.

it is really a pity because now that I have solved my initial motion sickness issue I can fly more than one hour exclusively in VR with Open XR tools to bypass steam VR and the immersion is incomparable even if I have also a track IR device and a hardware cockpit with 3 MFD cougar and their own small LCD in multi monitor. For sure with such a configuration I get more than 100 FPS in all kind of configuration...

[cptmrcalm]

One thing to bear in mind is that you might be experiencing issues with the drivers.

Apologies, I sped read the topic so I might have missed it. But if you are using WMR for Steam VR (Note: not WMR that you can access via the settings menu within Windows - but the actual "WMR for Steam VR" that you install within steam) then there have been at times versions of it that have upset a few gamers here and there.

Recently, they released two updates. One dated 6th Oct (1.3.58) and then one shortly after (1.3.60 <- in BETA state only).

Both of these version messed up DCS. Micro stutters -ghosting and general poor performance. For me, it crashed my system after 5 - 10 minutes.

After many hours of wasted re-installs and messing around with settings - it turned out that it was these updates that caused the issues. For me, the latest version (1.3.60) was a BETA version that I realised I had to opt into within steam to actually see it as available.

Once I did that and installed it I found it still didnt help. Some time later I found out that I could select: "lkg_release - lkg_release"  as an option within the WMR for steam vr 1.3.60 settings.

Performance for me now is certainly exceptable and playable as it had been before these two updates.

I run a 9900k (overclocked on all cores to 5ghz)

32 GB of ddr4 ram at 3200mhz.

3090 stock.

HP Reverb G2 set at 100% optics with reporjection off.

I could list the DCS settings here, but its a case of tweaking to you find the balance that you like.

apply them - test - tweak things off and on until you find the fluid motion you like.

 

But as I say, its certainly fluid enough for me. You always want more, but if I am honest - its certainly good enough for me to never return to a flat screen again.

 

 

 

Edited November 2, 2022 by cptmrcalm