Game is laggy in heavier missions with good constant fps

[302_Miro]

In more demanding missions, despite a constant 60 FPS, the game lags. Even if I lower the GPU's FPS limiter, it still runs at 80 FPS; the game doesn't run smoothly. I'm posting two videos: one is a mission that's more demanding on hardware, and lag is visible when turning your head, despite the same FPS. The next video shows the same thing, but the mission is on a server. In the video where the game lags, the "Load" value in the upper right corner is higher. But what's the load? The processor is idling, maybe 4 cores are working at 70%, GPU utilization is at 80%, and 16GB of VRAM is used out of 24GB. At both a constant 60 FPS and 80 FPS, I feel like I'm playing at 30 FPS.

 

 

 

Specs: 13900 KF, 4090, 64 DDR5, TIR5

[Valis]

Same here.

According to my widget the CPU is practically idling and my GPU rarely goes above 80%.

Adding just a few AI to a mission is enough to make it feel like V-Sync has been turned off.

By contrast DCS can have tons of AI flying and fighting in close proximity and everything remains smooth.

[302_Miro]

5 minutes ago, Valis said:

Same here.

According to my widget the CPU is practically idling and my GPU rarely goes above 80%.

Adding just a few AI to a mission is enough to make it feel like V-Sync has been turned off.

By contrast DCS can have tons of AI flying and fighting in close proximity and everything remains smooth.

At first I thought it was the old issue with the lagging trackIR in BoS, but when I'm driving on the taxiway, I look to the side without moving my head, everything lags, 60-80 fps, and I feel like I have 30 fps

[Husar]

Even though the FPS counter stays high, if the game load exceeds 60%, making TrackIR head movement feel very stuttery when looking around.

Edited July 21 by Husar

[Valis]

My favourite go-to mission to warm up is an 8v8 skirmish. The load thingy says 42% and it's already rough just panning around.

Considering the CPU horsepower everyone seems to enjoy what possible reason is there for a just few AI units to cripple performance so badly?

[Banzai]

I have the same issue. AMD Ryzen 7800X3D, RTX 5070ti, 32GB DDR 5 6000Mhz. 1440p capped at 120hz.

In my case when load goes higher than 20% looking around is not smooth. Even when I turn off TrackIR i can see stutters when rolling the plane left to right and back. 

When load is around 6-10%, for example in multiplayer Combat Box server, game runs fine with smooth movement of the ground and looking around. 

Same goes for simple free flight missions with few ground units. As soon I select a slightly more complex scenario, for example attacking troops, medium AA, medium target size, game becomes stuttery when looking around and rolling. 

My fps stays high, 120 most of the time but the choppiness of looking around makes it very unpleasant experience. 

I use a mix of high settings with indirect lighting off, grass off, mirrors off, terraine roughness off, native res 1440p and DLAA.

Fps capped at 120. Both GPU and CPU have headroom and frames are steady. I am baffled what is causing looking around being choppy.

As it is now SP is not enjoyable beyond a simple free flight mission or skirmish with couple of bots. I am not going to bother with the career if even simple scenario of attacking troops is not running smoothly.

 

 

 

[Valis]

34 minutes ago, Banzai said:

When load is around 6-10%, for example in multiplayer Combat Box server, game runs fine with smooth movement of the ground and looking around. 

Same here - anything over 12% (ish) and it's obvious something's going wrong. 

And as you note, graphics setting are irrelevant to the experience.

[Remontti]

I've noted same thing. Quick mission skirmish were quite smooth but after the patch the new mission types can be heavy with lot of flights. The fps is high but system load gets to 90 or occasionally over 100%. That's when game feels choppy. In the Black Thursday mission fps dips to 65 but it feels lower.

 

Graphics settings seem to very little (rtx 5080). I was wondering if I would need to upgrde my Ryzen 5800X to 5800X3D. Upgrading to AM5 would be a lot more expensive because then I would need to upgrade memory too. But given you're getting same experience with beefier cpus maybe it is better to postpone upgrades and wait if the game get's more optimized.

[YoYo]

I haven't flown online yet, but I've heard similar opinions. When the game is hosted on a server, it starts working quite well, and the user's computer load is low. In single-player, however, it's 60% or more. IL-2 Korea undoubtedly still requires work on optimizing its code and performance. Such high load causes further problems. I've also noticed my CPU reaching high temperatures (more over 80C +). I don't have any simulator that places such a heavy load on the system; even MSFS2024 generates less load for me.

[Valis]

32 minutes ago, YoYo said:

I haven't flown online yet...

It's lovely. I've yet to see the load go over 10%. Glass smooth.

Now obviously this is down to the relative lack of AI for the PC to handle, but the difference is stark.

Also, I noticed in your sig the 13900 CPU. I was considering that very chip to upgrade my PC, but from what you've said I doubt it would make any real difference. I'll wait to see what the devs can do.

Edited July 28 by Valis

[Husar]

42 minutes ago, Valis said:

It's lovely. I've yet to see the load go over 10%. Glass smooth

Most of the time yes , especially In combat box , but yesterday I have flown in Parallel 38 and load was high when ground units spawned - above 60%  , fps was high -165 but expiernce was not fluid, looking around with TrackIR felt choppy.

Edited July 28 by Husar

[Levadas]

Sup. Same thing here fps is high, around 90-100, but 99% frames drops really low from time to time down to 8-12 fps, so check them out. I use RX6700XT, most of the time it sits at 99% of usage, but ocassionally drops to 70-80% without any reason. My R5 8400f, despite being quite weak cpu, seems underloaded, at worst reaching 50% overall. The main culprit for now is ground vehicles. Cause everything works fine without them and 99% low somewhat stable. Probably something messed up with either their ai logic or damage calculation and saving. Probably unit virtualization is messed up, but i don't know if il 2 korea uses virtualisation or not.

[YoYo]

I've now checked the mission - ground attack (multi-vehicle convoy - column). The game is definitely too CPU-intensive. Interestingly, I set the graphics options to low/medium, without even any AA (off). Flying in VR. Oops :(. Temperatures and load are worse than I thought.

This still requires significant optimization. I should add that I've never achieved temperatures this high in any simulator (AIO water-cooled 360)! This means that even the CPU can experience throttling. While flying near the column (target), the FPS dropped significantly at the column (target), but that's not due to the GPU, but to the CPU.

Edited July 28 by YoYo

[Levadas]

1 час назад, YoYo сказал:

I've now checked the mission - ground attack (multi-vehicle convoy - column). The game is definitely too CPU-intensive. Interestingly, I set the graphics options to low/medium, without even any AA (off). Flying in VR. Oops :(. Temperatures and load are worse than I thought.

This still requires significant optimization. I should add that I've never achieved temperatures this high in any simulator (AIO water-cooled 360)! This means that even the CPU can experience throttling. While flying near the column (target), the FPS dropped significantly at the column (target), but that's not due to the GPU, but to the CPU.

Yep, problem deffinetly in ground vehicle optimization. Other areas have optimization problems too, mostly ai and cpu, ram,vram utilization related but not that signifficant. Don't know if there any gpu related optimization problems. The only thing is fsr quality looks too pixelated. Also for some reason the edge between air and land is really pixelated on graphics lower than ultra. So for now play on ultra, fps is lower, but no anoying edge. 

Edited July 28 by Levadas
Grammar

[302_Miro]

38 minutes ago, Levadas said:

Yep, problem deffinetly in ground vehicle optimization. Other areas have optimization problems too, mostly ai and cpu, ram,vram utilization related but not that signifficant. Don't know if there any gpu related optimization problems. The only thing is fsr quality looks too pixelated. Also for some reason the edge between air and land is really pixelated on graphics lower than ultra. So for now play on ultra, fps is lower, but no anoying edge. 

Maybye not only ground, because in Black thursday mission problem is much visible too for me.

[[I.B.]-=ViRUS=-]

2 часа назад, YoYo сказал:

The game is definitely too CPU-intensive.

Definetly. I have an old PC which i bought right before BoS EA started, the only upgrade i have ATM is 5080. In careere with full group of planes  i have just below 100% load in flight, when enemy planes arrive slowmo starts but framerate is decent.

[Levadas]

Только что, 302_Miro сказал:

Maybye not only ground, because in Black thursday mission problem is much visible too for me.

Yep. I forgot to mension it. The same thing happens in Black thursday, fine fps with enormous 99th percentile drops down to ~15-30 fps. Not as bad as ground anyway. Firstly i thought that this due to me having low RAM (I have only 16GB DDR5 5600MHz) or my CPU is too weak (R5 8400f), but after vehicle column expirience i come to conclusion that probably there is something wrong with optimization.

[pr0x]

R9 9950X3D, 5090 and I am experiencing the same thing. Solid 72 fps, but when I look at other planes they seem to stutter and lag a lot. It's as if the game throttles the physics simulation while keeping the framerate smooth.

[Levadas]

2 часа назад, reidarpeidar сказал:

R9 9950X3D, 5090 and I am experiencing the same thing. Solid 72 fps, but when I look at other planes they seem to stutter and lag a lot. It's as if the game throttles the physics simulation while keeping the framerate smooth.

In singleplayer? Cause in multiplayer this could be caused by ping. 

[pr0x]

4 hours ago, Levadas said:

In singleplayer? Cause in multiplayer this could be caused by ping. 

In multiplayer I never experience enough "action" for this to happen. It only happens in single player missions with 20+ planes in the air and/or a lot going on on the ground. Multiplayer for me is always buttery smooth.

I've noticed that this also seems to affect the camera. So when you turn your head in VR or you turn the plane, the whole game seems to render at a lower framerate, even though both the game and Virtual Desktop reports 72 fps. It is very similar to the effect you get when you orbit the external camera - then it _always_ renders at a lower framerate.

[YoYo]

8 hours ago, reidarpeidar said:

Solid 72 fps, but when I look at other planes they seem to stutter and lag a lot. It's as if the game throttles the physics simulation while keeping the framerate smooth.

That's right. I've noticed something like that too. Even though I have reprojection disabled in the headset and I'm running at 72 frames, in dogfights I see a certain stutter on other airplanes, despite stable frames. For example, reprojection used to give me this effect, meaning I could see enemy movement, but every other frame causes a certain lag. the fights in Korea look like you had reprojection turned on and were seeing every other frame. Strange.

[TPower]

It's a CPU scheduling/bottleneck, same issue with a 9950X, the devs are aware of the issue and it's being optimized, soon as I hit loads of around 70% the stuttering starts regardless of FPS which for me is nigh on a consistent 120FPS.

[Levadas]

3 часа назад, reidarpeidar сказал:

In multiplayer I never experience enough "action" for this to happen. It only happens in single player missions with 20+ planes in the air and/or a lot going on on the ground. Multiplayer for me is always buttery smooth.

I've noticed that this also seems to affect the camera. So when you turn your head in VR or you turn the plane, the whole game seems to render at a lower framerate, even though both the game and Virtual Desktop reports 72 fps. It is very similar to the effect you get when you orbit the external camera - then it _always_ renders at a lower framerate.

 

1 час назад, YoYo сказал:

That's right. I've noticed something like that too. Even though I have reprojection disabled in the headset and I'm running at 72 frames, in dogfights I see a certain stutter on other airplanes, despite stable frames. For example, reprojection used to give me this effect, meaning I could see enemy movement, but every other frame causes a certain lag. the fights in Korea look like you had reprojection turned on and were seeing every other frame. Strange.

In case of vr, don't forget to check your game latency. Via steamvr performance graph or VD performance graph.

Also check the network speed and bitrate. Some times too high bitrate can cause problems with some unoptimized games, like korea for now. Also AV1 despite being the most modern and efficient way of encoding and decoding can cause problems with certain games.

And, as i mentioned before, check your 99th fps percentile/1% lows. Some times the fps drops lasts less than second, so fps counter doesn't shows any drops.

Don't personally use vr for flight sims, cause i have quest 3s, resolution is too low and no pancake lenses. Wish you all good luck.

[Levadas]

1 час назад, TPower сказал:

It's a CPU scheduling/bottleneck, same issue with a 9950X, the devs are aware of the issue and it's being optimized, soon as I hit loads of around 70% the stuttering starts regardless of FPS which for me is nigh on a consistent 120FPS.

Nice to hear that this problem had been acknowledged, hope it get fixed by release. Cause after the release the amount of players will increase, not sure how significant, but anyway it will. There for even more bugs will be discovered and posted here.

[pr0x]

11 minutes ago, Levadas said:

Also check the network speed and bitrate. Some times too high bitrate can cause problems with some unoptimized games, like korea for now.

Yeah, I've noticed that it doesn't like 200mbps for sure. I turned the bitrate down to 100 and turned on two-pass encoding instead. That gives me about the same clarity as 150, but without the head jitter caused by the latency. I've come to believe that Virtual Desktop's performance metrics can't really be trusted. 100mbps with two-pass encoding shows up as only a couple of ms less latency, but it is significantly smoother than 200mbps.