Poor performance in VR on 1080ti. Please help!

[Norman]

I'll start off by saying that VR experience in BOK is breathtaking. The sense of immersion is second to none. One of the reasons I upgraded my GPU to the 1080ti is in anticipation for BOK going VR.

 

On my 4K monitor I've been consistently able to attain 60fps vsync with everything maxed no problems. However, in VR with the oculus rift, I have been having trouble maintaining even 45fps especially when close to the ground or when there's many planes in the air. Even with settings turned to Low and everything turned off, sometimes fps dips low enough for ATW to kick in. Afterburner software tells me that only 35-50% of my GPU is utilised most of the time. Under the same conditions, my graphics card has. I problem outputting consistently high frame rates on my 4K monitor.

 

Anyone else experiencing this? What am I doing wrong? Thanks for any help

[Urra]

That's with the hud on or off during flight?

[coconut]

Pretty much everybody has that problem, I would think, and the reason is that the game is CPU-bound. VR requires twice as many frames as single screen. That's like 180FPS on a single monitor. It is true that the FOV is typically less than on a single screen, where people like to fly zoomed out for situation awareness, but still...

 

I'm afraid that you will just have to live with ATW when close to the ground. Or accept less than 90FPS. Or buy the latest fastest intel CPU and overclock it.

 

It would be nice if we could have VR-specific settings where we keep high/ultra quality for planes and clouds, and low for terrain and ground objects. Personally I can't really say I see any difference between the settings, given the low resolution of the OR, except for clouds and forest range (which is noticeably short even at Ultra anyway).

 

I suspect the devs have already implemented something like that, but I'm not sure. I was flying with a friend the other day, and he could see buildings I could not see without zooming. I was flying in VR with Ultra settings at that time.

 

For reference, flying on the Moscow map near the Moscow, I get 45-50 FPS looking at the city, 70-80+ looking at the ground away from it. I tried playing with settings, but no matter what I did, Moscow was hard to render. No biggie for me, I have no problem tolerating "low" FPS, even in VR, as long as it does not stutter.

 

You can try turning on the performance overlay from Oculus Tray Tool (if you have a Rift, that is). If it shows -100% in "performance headway" you are hitting the lower limit at 45FPS (which is bad). Anything between 0% and -100% will trigger ATW. Above 0% you are happily flying at 90+FPS.

Edited April 17, 2017 by coconut

[Norman]

That's with the hud on or off during flight?

HUD off does give me more fps but still not what I'd expect with a 1080ti.

 

Thanks coconut for your reply. I guess I have to temper my expectations. I just have been reading reports from other forum members of 90fps constant with even a 1070 so I was quite surprised with my performance. I forgot to mention that my cpu is an older i7 4770 so maybe that's the bottleneck. I figured that if the GPU can give me butter smooth performance with everything on at 4K that it should also be able to handle VR resolution.

[coconut]

The way I see it: CPUs send triangles to GPUs, which turn them into pixels. More pixels = more work for the GPU, but not for the CPU. More triangles = more work for the CPU and the GPU, but currently it takes more than a CPU core to saturate a GPU. Because the game is currently limited to a CPU for its rendering, the limiting factor is the number of objects, not so much the resolution.

 

We should produce a couple tracks to evaluate performance, and let people post recordings with the frame counter on. That's the only way to get reliably comparable results.

 

The good news is that we have extra GPU power available for the day when higher resolution VR headsets come out

 

EDIT: here is a link to two tracks. ref1 is a fight with 4 stukas above a heavy cloud cover, ref2 is a low altitude flight on the outskirts of Moscow. https://1drv.ms/u/s!AtoivprUAORRrAjkhCv8rJvRMcmS

 

For me the settings don't matter too much. I might just as well fly with Ultra, I'm below 90 anyway when I'm close to planes or to the ground. On another track, far from Moscow, strafing units on the ground, I could stay at or above 90 most of the time on Low, which I could not on Ultra. I'll probably stick to Ultra for the better cloud quality. It's hard aiming at planes in Low when there are clouds behind the target.

Edited April 17, 2017 by coconut

[Norman]

I have been able to run at 4K at ultra pretty smoothly, so I figured that maybe it will be a breeze for VR since the resolution is lower? Perhaps it still requires some optimization. But the sense of presence is definitely there. ATW works great except for some ghosting for planes through the propellor blades.

[Slugga]

Pretty much everybody has that problem, I would think, and the reason is that the game is CPU-bound. VR requires twice as many frames as single screen. That's like 180FPS on a single monitor. It is true that the FOV is typically less than on a single screen, where people like to fly zoomed out for situation awareness, but still...

 

I'm afraid that you will just have to live with ATW when close to the ground. Or accept less than 90FPS. Or buy the latest fastest intel CPU and overclock it.

 

It would be nice if we could have VR-specific settings where we keep high/ultra quality for planes and clouds, and low for terrain and ground objects. Personally I can't really say I see any difference between the settings, given the low resolution of the OR, except for clouds and forest range (which is noticeably short even at Ultra anyway).

 

I suspect the devs have already implemented something like that, but I'm not sure. I was flying with a friend the other day, and he could see buildings I could not see without zooming. I was flying in VR with Ultra settings at that time.

 

For reference, flying on the Moscow map near the Moscow, I get 45-50 FPS looking at the city, 70-80+ looking at the ground away from it. I tried playing with settings, but no matter what I did, Moscow was hard to render. No biggie for me, I have no problem tolerating "low" FPS, even in VR, as long as it does not stutter.

 

You can try turning on the performance overlay from Oculus Tray Tool (if you have a Rift, that is). If it shows -100% in "performance headway" you are hitting the lower limit at 45FPS (which is bad). Anything between 0% and -100% will trigger ATW. Above 0% you are happily flying at 90+FPS.

 

 

Whilst i would normally agree. I would actually doubt this is CPU bound. My CPU is an i7-3820 running at 4.6ghz. When using my Rift and looking at the ground at all, I get locked at 45fps by ASW/ATW.  How ever during this point it is only sitting at 20-30% cpu usage.. and my GPU sits at about MAYBE 60% but most of the time 30-50% (i have tried forcing ATW off with Oculus desktop Tool, and SteamVR but I don't get any joy)

 

Now with my Vive, i get the exact same utilisastion stats, but is it not locking it 45 until its a busy screen with lots of planes. Looking at the ground i will be getting 89FPS most of the time How ever, look at 6 bombers in formation that I am escorting.. Nose dives to ~60 then i can start seeing the ATW separation/double vision on fast moving objects.

 

Its a much smoother experience on the Oculus as the frame drops are slightly less noticeable. How ever the tearing from ATW on the crosshairs etc, drives me nuts. and the fact that it is locking to it much more frequently than the vive has me reaching for that at the moment. (as well as the colour saturation bump vs rift)

 

but my main concern on this is that the CPU and GPU utilization are not even close to 100% and I am seeing frame drops.

Edited April 21, 2017 by Slugga

[Setras]

but my main concern on this is that the CPU and GPU utilization are not even close to 100% and I am seeing frame drops.

Indeed. I have the same issue - during the FPS drops, i have less load on the CPU and GPU. And i have no ideas what causes those drops. I had paused the game, and just looking at the smoke causes load drop and FPS drop.

[=TBAS=Sshadow14]

yeah seems to be a driver problem

a friend in discord also having this issue..

He can run game Ultra @ 4K and get 100-140fps on Monitor
But Has to run Balanced Preset @ Rift/vive Res of 1440P and gets 45-95FPS Jumping all over place.

Where as 1080Ti should be able to run VR @ Ultra with ALL options turned on (hdr,ssao,msaa)
and still get Solid 90FPS

(unless the marketing for 1080Ti is just a big scam and its barely better than a 1060??
Anyone else got VR working on 1080Ti in other game without FPS lose?)

[OrLoK]

I cant speak for a ti but my 1080 on ultra and view distance cfg will regularly go to 45 with options off and ss @1.3

[Slugga]

Yeah very interesting. At least I know I am not crazy. Or it is just my setup. But yes very strange indeed, hopefully there is a hotfix soon.

 

How many people seeing this are on a '10 series card?'

[coconut]

 

 

How ever during this point it is only sitting at 20-30% cpu usage

 

That's pretty much max CPU usage for this game on a core i7 with hyperthreading. My i5 goes to 40% at most.

[Slugga]

That's pretty much max CPU usage for this game on a core i7 with hyperthreading. My i5 goes to 40% at most.

 

Huh, This makes no sense? if the game is not able to use more than 1 core for rendering then you shouldn't be seeing 40% usage should you? the ratio of core is still the same, the i7 should be getting much better frames if this is the case not just sit at a lower idle. as well as if it was capped it should be sitting at minimum 25% usage non stop which is also not what we are seeing.

 

What ever the cause, it does need to be optimized some how, as its not like we haven't had multicore 64 bit cpus for a while now.

[coconut]

This game doesn't just do rendering. The 3D rendering is likely limited to one core.

[Wolf8312]

This is the thing I am wondering about, how is this problem to be solved? It doesnt seem like a bigger CPU or GPU would make a diffrence so what would exactly, is it a problem with Nvidia or something the developers need to fix or both?

[coconut]

Not much you can do as a user. Nothing NVidia can do (well, they could fix their drivers for the guys with 780s, but that's another story). Realistically I don't expect devs to do anything either, they can't just spend 6 months to rewrite the engine to take advantage of all cores, make sure it remains a smooth bug-free experience across the range of configurations.

 

Learn to like ASW, or live with suboptimal framerates, or avoid missions with lots of planes. Personally I'm very happy with the current situation. Sure, I'd love to have 90 FPS all the time, but that's not the kind of experience ambitious flight sims can guarantee in all situations. Knowing that focus in development will now shift away from VR and back to other stuff needed for Kuban, I just hope VR will remain as smooth as it is now.

[Wolf8312]

Yeah me too to be honest we really couldnt ask for more or a better VR flight sim at this present point in time. I was just curious to be honest though there is another flight sim I desperately want to improve somehow! Battle of stalingrad though I'm a very satisfied customer!

[coconut]

I could be wrong about max CPU usage of course. Maybe there is something wrong with the way the compositor and the game interact. One way to check is to compare with running in flat mode. What do the GPU and CPU loads look like? In my case I think they are similar, but it was a while since I checked.

[coconut]

Actually, there is a difference between flat mode and VR. In flat mode I can reach over 40% CPU utilization, if I leave frame rates unlocked. It's also rather unpleasant and stuttery when I do that, despite high FPS well above 100.

 

In VR with dynamic textures disabled (full), I tend to get stuck at 45 FPS with 60% GPU utilization and at most 30% CPU utilization.

 

In VR with dynamic textures enabled (0.5), CPU utilization goes up a bit. Not all the way up to flat mode, but between 30 and 40%. FPS stays up at 90. Until it can't keep up (flying low over the outskirts of Moscow), in which case it goes down to 45 and lower CPU utilization.

 

What I think is going on is that the devs have implemented a throttling mechanism in VR to keep stutters away at all costs. There is one we know of, the dynamic resolution thing, and maybe others we don't know of.