VR Performance in DCS World

Hey dudes and dudettes. We have our own forum now so we might as well use it. This is a continuation of a chat which got lost in the middle of the, now historic, Oculus mega thread.

Rift/Vive/Other are free to join in the discussion. We are all one in this adventure.

Is anyone here able to maintain ~50fps or greater consistently in the latest update? It doesn't matter what I fly, whether I fly alone or with AI, whether there is a war or not, whether I use mirrors or not or whether I turn everything to low or high... I really struggle to maintain decent FPS.

Problem areas for me are built up areas. If I even look in the direction of them I will see huge frame rate loss and stuttering. I go from consistent 90fps sitting on the ground at Batumi to low 30s-40 when I look to the north. It happens even when the town is obscured by other objects such as trees. On the CV1 this causes very distracting stuttering as you move your head.

I run a 4670k at 4.5GHz (no thermal throttling) and a EVGA 980Ti with DCS on its own 850Evo SSD.

I assume this is a software optimisation issue as my hardware is fairly up to date (CPU is probably the weakest link) so I'm wondering if any clever people here have worked out a way to lessen the frame hit through a tweak or setting change.

I don't remember this happening before the latest update - but I was running on the monitor so the frame drops may have been less noticeable.

If you are having no issues with stuttering please post your rig and settings - and any things you have done which may have saved you from the stutter!

Lower Visibility Distance.

Or wait for SLI support as per: http://forums.eagle.ru/showpost.php?p=2744497&postcount=6841

Then try to figure out how the hell you can make room for another card! :)

But if you've already tried everything at low setting (and making sure you use FLAT shadows - two locations you can set it) then your rig may not be able to keep up.

I don't have my CV1 yet, but on DK2, I can maintain 75FPS.

I have the same problem. Specs in sig.

I've tried mustang's 1.2 visibility mod, turning off tree shadows, and just about every conceivable mix of in-game options. Low settings or ultra, there's very little difference in frame rate. Turning off shadows entirely just about completely eliminates the problem, but then I really miss the cockpit shadows.

I never had trouble holding 60fps solid when I was playing on a TV at 1080p, and when it did slow down it was because there was a lot of action and one of the CPU cores would be maxed out. With the current performance issue, no CPU core ever goes above ~60%, and GPU is often around 60% as well. I can force it up to about 80% if I max out all the post-processing options, but that's about it.

1 Viewport @ 1080p vs 2 Viewports at 1080x1200 each at 90Hz.

Then why the low CPU/GPU utilization?

DCS is using 2 therads... 1 for the sim engine and 1 for the sound (the soung engine won't use much CPU cycles anyway) so at best DCS will use around 30% of the CPU power for 4 core processors.

I think the shadows are the biggest impact on FPS by far but they are rendered on graphics card, not the CPU. I was thinking that DCS should get another pre-set for Graphics options, namely for VR. I can't wait to get my OR to see how it goes, and if I can change some settings to improve performance... but this is few months away for me.

Rendering for VR is a race against time. You only have to miss the timing window by a single millisecond to completely halve your framerate.

Even with ATW you will experience the side effects of that halving. At least with ATW you will not be made sick by a low framerate. The same is true for Valves reprojection.

Compared to VR, rendering to a normal screen is lot easier because it is not latency dependent. It is actually quite common for a graphics driver to queue up several frames (at the cost of latency) to dramatically improve framerates. You dont normally notice this high latency in flightsims BUT in VR you absolutely do which is why the graphics driver can't use this technique to queue frames.

This is why a GTX980TI can get 200fps (at high latency on a monitor) but can't consistently beat the 10ms timing window to keep the framerate from dropping below 45fps under high visual loads in VR. When it comes to VR rendering, the rendering challenge very different; hitting the timing window every single frame is now the most important thing.

I do think that people should be disabling LUA exports, track recording and other DCS features that could affect VR performance. VR is demanding ... don't carry extra CPU/GPU load.

OK I edit this post to be more EXACT because people are still posting about perf. I said don't carry extra CPU/GPU load BUT that was the wrong term to use. More accurate to say - avoid LATENCY.

You can have your GPU at only 50% load because the scene is taking TOO long to render one frame and that frame is being discarded and your are only running at 45fps or lower. Your card will not load up because lots of frames are being discarded. This is logical.

If your GPU cannot render EVERY frame in 10ms there are not many things you can do. You could try to overclock the core clock of GPU. Increase of 10% might save you 1ms which could make a difference if your very lucky. OR you can try to reduce scene complexity that adds to the total draw time.

Hi guys/gals with HMDs. One quick question. I read that zooming keys don't work in VR, but how about snap views? I use them with A10 to work with radios and CDU even on a monitor. Would be useful in VR too...

I have the exact same issue as the op!

Using Strix GTX970.,

Graphics settings makes absolute no difference in stutter nor visiblity improvements tbh.

Graphics card usage <70%

I edited my previous post to more obvious.

You can have your GPU at only 50% load because a single frame is taking TOO long to render (more than 10ms) and that frame is being discarded and this causes the rendering engine to fallback and render only every second frame so you get 45fps. If your GPU can't render frames in 20ms then you will discard even MORE frames. Thus your card will not load up because lots of frames are being discarded. This is logical.

If you want to load up your card you HAVE to render each frame within the budgeted time.

Vicx, that makes perfect sense. I noticed that the detailed in-game fps counter shows the time spent on various elements, and if it wasn't going to make it's 11ms window, it'd drop to 22ms. The confusing part was that sometimes the sum of all displayed tasks would be under 10ms, yet it wouldn't make the 11ms window. I guess there's some more stuff going on back there that doesn't get shown in the detailed counter.

It seems there's not much to do about it on the user end. We have to wait for ED to figure out what's causing the high-latency in these latest builds, because there's nothing that can be done to fix it with in-game options.

...

 

I think the shadows are the biggest impact on FPS by far but they are rendered on graphics card, not the CPU. ...

yep, can concur

i've turned shadows off

would rather have shadows - they look great

but FRs are more important to me

One thing about that frame counter again; shadows have the biggest impact on frame rate, but the contribution to frame time is usually less than 0.5ms. I don't know what's going on there, there's gotta be some background issue.

Here are my settings from v1.5. I keep everything low to keep frames high with VR, and a lot of fine detail is lost anyhow with the DK2 so I don't waste the frames. I run a solid SIM frame rate of 75 all the time except when flying over bigger towns with a lot of buildings. I see the object count in the frame rate counter get above 4000+ when the frames drop to the floor. Fortunately ATW makes it a bit easier to bear now.

Here are my settings for my CV1:

This setting works great for me. The presence in the Cockpit is unbelivable and the Huey is much more easy to fly than with TrackIR. Okay, the picture isn´t 100% sharp and the settings are low, but this is the price to pay at the moment for this unbelivable presence!

My Rig:

- Core i7 6700k

- GTX 970 Jetstream

- SSD 850 Evo

- Win10 Pro

on a Lower End GPU, I Have Everything On LOW, Except Textures, those are on High, and Visibility Range on Medium to avoid Apparent pop ups.

Everyone is having problems with VR, even on low settings yet we have Mr. Wagner who commented a while ago saying VR gameplay in DCS is great and flawless using both headsets. What a misleading information!

I'm now cancelling my Vive preorder and the only thing I regret about is that a couple of months ago I've spent so much on the high end PC just mainly for VR in DCS and it turns out that not only I have to set everything on LOW in graphics settings but even then I can't have a smooth flight. I don't care how immersive you feel while wearing this useless (in DCS) headset through which you can't even see and appreciate high details of the sim even with 980ti.

I bet DCS is at least 2 years away from a good VR experience and about 5 years from calling an excellent experience.

So much hype with this BS VR on DCS forum!!!:hmm:

Everyone is having problems with VR, even on low settings yet we have Mr. Wagner who commented a while ago saying VR gameplay in DCS is great and flawless using both headsets. What a misleading information!

I'm now cancelling my Vive preorder and the only thing I regret about is that a couple of months ago I've spent so much on the high end PC just mainly for VR in DCS and it turns out that not only I have to set everything on LOW in graphics settings but even then I can't have a smooth flight. I don't care how immersive you feel while wearing this useless (in DCS) headset through which you can't even see and appreciate high details of the sim even with 980ti.

I bet DCS is at least 2 years away from a good VR experience and about 5 years from calling an excellent experience.

 

So much hype with this BS VR on DCS forum!!!:hmm:

Take a deep breath mate. VR rendering is complicated stuff. I have 0 doubt ED will resolve the issues were having. I mean it hasn't even been a month since they came out. Basic support has only just been implemented.

Regarding the topic, everything is fine until I look at some buildings.

Wow!!! I'm having so much fun now with VR and DCS... and that's no HYPE!

If anyone is having jumpy situations, possibly like micro stutters in VR, our main coder has found a solution to his in CloD:

http://theairtacticalassaultgroup.com/forum/showthread.php?t=21356&p=226542&viewfull=1#post226542

@RUS38

Relax a little, it's supported in a beta and alpha version of DCS, which means it's WIP. It's also the reason we're here discussing it, to figure out what's up and how to go about fixing it.

The performance issues are not insurmountable, and I'm sure we'll have liquid smooth frames before half the people out there even get their HMD's delivered.

Everyone is having problems with VR, even on low settings yet we have Mr. Wagner who commented a while ago saying VR gameplay in DCS is great and flawless using both headsets. What a misleading information!

I'm now cancelling my Vive preorder and the only thing I regret about is that a couple of months ago I've spent so much on the high end PC just mainly for VR in DCS and it turns out that not only I have to set everything on LOW in graphics settings but even then I can't have a smooth flight. I don't care how immersive you feel while wearing this useless (in DCS) headset through which you can't even see and appreciate high details of the sim even with 980ti.

I bet DCS is at least 2 years away from a good VR experience and about 5 years from calling an excellent experience.

 

So much hype with this BS VR on DCS forum!!!:hmm:

No hype, it's amazing on my system, with every setting maxed and time warp doing it's thing. Who are you going to believe, the people who have got things dialled in or the people who haven't?

And if you are only interested in VR for DCS, then you have no gaming soul.

If anyone is having jumpy situations, possibly like micro stutters in VR, our main coder has found a solution to his in CloD:

 

http://theairtacticalassaultgroup.com/forum/showthread.php?t=21356&p=226542&viewfull=1#post226542

At this point, I'm sure it's just placebo effect, but I really think it helped! :thumbup: I didn't see any major difference in frame rate, but it does feel smoother. Or at least I think it does.... But isn't that what really matters? :D

BigDuke, what computer system did NASA let you borrow?! If I want to even think about seeing 90fps in the rift, max settings across the board aren't an option. Granted even 45 looks pretty good with ATW, and even 30 looks great if I'm putting about looking at the flowers. Unfortunately, 45 isn't quite so nice if I'm maneuvering hard in a dogfight; the ghosting is very distracting.

Take a deep breath mate. VR rendering is complicated stuff. I have 0 doubt ED will resolve the issues were having. I mean it hasn't even been a month since they came out. Basic support has only just been implemented.

 

Regarding the topic, everything is fine until I look at some buildings.