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

[trevoC]

On 11/1/2022 at 2:21 PM, Swson said:

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 I agree that the graphic engine is outdated and I'm very surprised that the CPU is not really used (max 20%) even in single thread compared to the GPU; I'm using a AORUS 490 chipset with a 10700K I7 and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...

Your CPU is most definitely not running at 20% utilization how you might think it is. You are looking at utilization across all cores. One of those cores has the DCS main thread and it is most likely limited by that core. DCS suffers as most games that can't utilize multi-cores well (which is most games btw, even the multi-threading games) by the main "loop" of the game that is trying to send instructions to the GPU which is usually doing them much faster than the CPU can send them. Programming out this behaviour of a main thread in your game is more difficult than most people think. I don't envy ED in this respect. I'm running a 5900x OC'd 20% and it is absolutely the limiting factor with my 3090 which can be as low as 50% (usually around 60%-90%) utilization.

[linside]

I tried to play tonight but the fps are about 40 and in some moments even less (medium detail, open xr). Before the patch I had 15-20 fps more. I will do as many friends and will wait to play until they have solved the problem. I'm sad but with this patch I think the time for multi treading has become precious. 

 

I have G2 and 3080.

 

[St4rgun]

I hate to say but I had to rollback to 2.7.18.30765 for the better performance. Which is a pity because I liked the new FPS counter, dynamic weather, new lighting on PG and the raindrops on the canopy glass so much, but after more testing it turned out that 2.8 in this state is not for me in VR, sorry.

I really hope that ED team can find a quick solution to counter this performance drop in VR.

[zildac]

Despite my initial disappointment, I have managed to get back to almost 2.7 levels of performance, and it was solely by settings terrain shadows to OFF. Whilst not ideal, it's an acceptable short term workaround for me. One thing I have noticed and others have also reported is there appears to be some additional reflections/shadows on the canopy now (Harrier and Hornet I have seen this on personally). Even with canopy reflections off and shadows to medium these are quite well-defined shadows/reflections, and I suspect they are having an impact on performance too. This can be easily seen by starting the F18 ready on the ramp in the Caucasus and looking at the reflection/shadow of the HUD frame on the left side of the canopy. This effect was not present in 2.7 as I recall.

[pimp]

I've said this for years that ED needs a dedicated VR engineer. An engineer that focuses only on VR. I realize a lot of the core development effects VR, but a dedicated developer would definitely improve the frequency and current quality of the sim. The performance and experience has definitely gotten better over the years, but I believe if someone was solely focused on VR it would be much better by now.

[Bullant]

Shadows to off in 2.8 gives me near 2.7 performance. I'd love 90fps in VR, but I know that isn't happening any time soon. I was flying the Huey in Marinaris, and the P51 over the Channel tonight and getting 40fps+ on my G2 with pretty much everything maxed and MSAAx4 so that is keeping me pretty happy.

 

[wheelie]

Guys apparently if you're running 12/13th GEN CPU's you ned to set DCS to only run on the P cores, lots of discussion around this on various discord groups and tying DCS to P cores fixes quite a few issues around stuttering especially with a 4090 GPU in the system as well.

Just a heads-up.

[ColinM9991]

19 minutes ago, wheelie said:

Guys apparently if you're running 12/13th GEN CPU's you ned to set DCS to only run on the P cores, lots of discussion around this on various discord groups and tying DCS to P cores fixes quite a few issues around stuttering especially with a 4090 GPU in the system as well.

Just a heads-up.

Is there a guide forshowing people how to do this? Not everyone will have the know-how to perform such a task. Certainly, not everyone will be comfortable messing around with BIOS settings.

[wheelie]

Thankfully it's not a BIOS setting Colin i believe its a program called Process Lasso, apparently the program can be used to forbid DCS to use the E-Cores and set DCS to high priority.

This essentially forces DCS to have a higher priority of the CPU's time and limits DCS to only use the performance cores.

Hope this helps buddy.

[Jarhead0331]

On 10/30/2022 at 7:06 AM, 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.

 

What planet are you from? 60FPS in VR is "poor performance" and 90FPS is "low but marginally acceptable"? In my world, 60FPS in VR is very good and 90FPS is exceptional.

Edited December 20, 2022 by Jarhead0331

[zildac]

1 hour ago, Jarhead0331 said:

What planet are you from? 60FPS in VR is "poor performance" and 90FPS is "low but marginally acceptable"? In my world, 60FPS in VR is very good and 90FPS is exceptional.

 

Quite....not sure he's actually played DCS in VR 180FPS is excellent...damn right it is, and impossible

[trevoC]

Yeah, those numbers are out to lunch.

I target 45 fps on Marianas islands in a huey on ground level (which is damn good), usually settle for 40ish which gives me a good 60-80 in the air with most aircraft and not too much going on.

plenty playable at 45 fps (actually thats an understatement, its very playable). 

In short, I'm running a 5900x Overclocked 20% (water cooled) and a 3090. Settings are all high and 4x AA on an HP G2

[Marco Schaap]

I'm gonna test this tonight: 

 

[Gunfreak]

5 hours ago, trevoC said:

Yeah, those numbers are out to lunch.

I target 45 fps on Marianas islands in a huey on ground level (which is damn good), usually settle for 40ish which gives me a good 60-80 in the air with most aircraft and not too much going on.

plenty playable at 45 fps (actually thats an understatement, its very playable). 

In short, I'm running a 5900x Overclocked 20% (water cooled) and a 3090. Settings are all high and 4x AA on an HP G2

45fps with motion projection is perfectly fine be me. But I want it to be stable, no matter what map I'm on. And no matter if I fly a free flight or in trying to shot down a 72 B17 bomber formation in my Kurfyrst.

If I can play Reflected's ww2 Campaigns with default unit numbers in VR and it's smooth. Than I'll be happy.

[trevoC]

10 minutes ago, Gunfreak said:

45fps with motion projection is perfectly fine be me. But I want it to be stable, no matter what map I'm on. And no matter if I fly a free flight or in trying to shot down a 72 B17 bomber formation in my Kurfyrst.

If I can play Reflected's ww2 Campaigns with default unit numbers in VR and it's smooth. Than I'll be happy.

45 is the lowest. Marianas in the Huey is about as bad as it gets. That doesn't mean that a campaign with a hundred bombers dropping 20 bombs each won't give you some pain. I also do not use motion reprojection, can't stand it.

Not sure how I implied it wasn't stable. Its a stable 40-45 fps minimum with a head of around 90 (usually around 70 in the air)

Doesn't mean I haven't experienced a moment or two (during hours of play) that produces a lower fps. Usually near the ground and a bunch of stuff getting hit (some moments during paradise lost campaign). 99% of the time I'm fine.

Do I want better performance? Yes.

Is DCS unplayable in VR? Absolutley Not. It's plently playable.

[ColinM9991]

19 hours ago, wheelie said:

Thankfully it's not a BIOS setting Colin i believe its a program called Process Lasso, apparently the program can be used to forbid DCS to use the E-Cores and set DCS to high priority.

This essentially forces DCS to have a higher priority of the CPU's time and limits DCS to only use the performance cores.

Hope this helps buddy.

 

Perfect, many thanks.

[Gunfreak]

1 hour ago, trevoC said:

45 is the lowest. Marianas in the Huey is about as bad as it gets. That doesn't mean that a campaign with a hundred bombers dropping 20 bombs each won't give you some pain. I also do not use motion reprojection, can't stand it.

Not sure how I implied it wasn't stable. Its a stable 40-45 fps minimum with a head of around 90 (usually around 70 in the air)

Doesn't mean I haven't experienced a moment or two (during hours of play) that produces a lower fps. Usually near the ground and a bunch of stuff getting hit (some moments during paradise lost campaign). 99% of the time I'm fine.

Do I want better performance? Yes.

Is DCS unplayable in VR? Absolutley Not. It's plently playable.

Playable very dependent on mission. 

Reflected campaigns aren't Playable in VR with the default unit number.

Even the new ww2 missions released by ED, loosely based on Dieppe aren't Playable in VR.

[5ephir0th]

Definitively something is wrong in op system, on my PC (pretty similar) i get 72 stable fps even on a populated super carrier, 2700x2800 per eye, MSAA x2 and medium/high details, clouds on ultra

[trevoC]

5 hours ago, Gunfreak said:

Playable very dependent on mission. 

Reflected campaigns aren't Playable in VR with the default unit number.

Even the new ww2 missions released by ED, loosely based on Dieppe aren't Playable in VR.

Yes, I have been in a reflected campaign when the bombs drop and experienced a slide show (for that very moment, rest of mission is fine)

"Reflected campaigns aren't playable" < not true, I did finish that mission very easily and finished paradise lost campaign and others with little slowdown at all (I think in paradise lost there was a single mission when being shelled at one of the outposts that brought my game to a state that I had to wait 10 seconds or so before resuming)

I wouldn't call either of these "unplayable". I enjoyed both campaigns thoroughly.

A comment from reflected mentioned that he made changes to the WWII campaign recently to drop less bombs to help with this. I haven't tested since this change.

"Reflected campaigns aren't playable in VR with the default unit number" < is kind of like saying that DCS isn't playable in VR at ultra high settings at 8k per eye. Yes, you may have to make some considerations for VR. Thats a thing. VR is all consuming and until ED brings changes to how the draw calls are made (either via vulkan directly to GPU, or separating the main thread and logic thread to separate processors) this will always be a thing.

You will need to either lower the requirements against your hardware (less units or graphics) or increase your hardware. This is PC gaming (especially in flight sims). Its always been this way.

[Gunfreak]

38 minutes ago, trevoC said:

Yes, I have been in a reflected campaign when the bombs drop and experienced a slide show (for that very moment, rest of mission is fine)

"Reflected campaigns aren't playable" < not true, I did finish that mission very easily and finished paradise lost campaign and others with little slowdown at all (I think in paradise lost there was a single mission when being shelled at one of the outposts that brought my game to a state that I had to wait 10 seconds or so before resuming)

I wouldn't call either of these "unplayable". I enjoyed both campaigns thoroughly.

A comment from reflected mentioned that he made changes to the WWII campaign recently to drop less bombs to help with this. I haven't tested since this change.

"Reflected campaigns aren't playable in VR with the default unit number" < is kind of like saying that DCS isn't playable in VR at ultra high settings at 8k per eye. Yes, you may have to make some considerations for VR. Thats a thing. VR is all consuming and until ED brings changes to how the draw calls are made (either via vulkan directly to GPU, or separating the main thread and logic thread to separate processors) this will always be a thing.

You will need to either lower the requirements against your hardware (less units or graphics) or increase your hardware. This is PC gaming (especially in flight sims). Its always been this way.

If you're not gonna play reflected campaigns on full scale, you might as well go play IL2, with the tiny scale and scope.

I'm not talking about bombs. I'm talking about playing the mission. The game goes into single low 20s high teens fps,while I'm still many miles away the bomber formation. 

I made a small  CAS mission in the P47, mabye a dozen units on each side. When they fire at each other the mission literally stops half a second at a time. 

 

Playing the Dieppe inspired missions from ED, as soon as the flak goes up and bombs fall again low 20s and very choppy. And that's not even a particularly big mission. 

[trevoC]

6 hours ago, Gunfreak said:

If you're not gonna play reflected campaigns on full scale, you might as well go play IL2, with the tiny scale and scope.

Not sure why you are here then. You need to either lower your settings or increase your hardware requirements. Welcome to PC Gaming. Its a balance. Not sure of any flight sim ever worth playing that didn't push hardware limits.

Does DCS need a major engine overhaul? Yes, that would be nice, and help a lot, but its hardly unplayable. I can run the game in ultra in 4k (pancake) on any mission with little slowdown.

I choose to push the boundaries in VR at high but realize I'm in newer territory's that requires a balance. I'd be guessing that you should spend more time finding that balance on your setup before expecting it to perform better than it can. I'd suggest OpenXR and foveated rendering. Works wonders on my setup.

[Gunfreak]

6 hours ago, trevoC said:

Not sure why you are here then. You need to either lower your settings or increase your hardware requirements. Welcome to PC Gaming. Its a balance. Not sure of any flight sim ever worth playing that didn't push hardware limits.

Does DCS need a major engine overhaul? Yes, that would be nice, and help a lot, but its hardly unplayable. I can run the game in ultra in 4k (pancake) on any mission with little slowdown.

I choose to push the boundaries in VR at high but realize I'm in newer territory's that requires a balance. I'd be guessing that you should spend more time finding that balance on your setup before expecting it to perform better than it can. I'd suggest OpenXR and foveated rendering. Works wonders on my setup.

I have an i9 9900k, 3090, and 64 gig ram, it's perfectly reasonable to expect me to be able to play official missions released  by ED at full scale.

Open xr har zero effect for me and it just way more trouble for what it's worth.

[trevoC]

7 hours ago, Gunfreak said:

I have an i9 9900k, 3090, and 64 gig ram, it's perfectly reasonable to expect me to be able to play official missions released  by ED at full scale.

Open xr har zero effect for me and it just way more trouble for what it's worth.

I don't think it is reasonable to expect VR to perform top notch yet at higher resolutions or settings. VR is relatively new and doubles the draw calls on an already demanding game. I think VR users need to have more reasonable expectations. By no means would playing this in 4k or 1440p be difficult.

Secondly, not sure how OpenXR is too much trouble for an effective doubling of fps. You literally need to copy one file over to the DCS directory for it to work and then enable one of the presets in game. If implemented properly (file copied) it would be impossible for this not to have an effect as it would cut the required resources to be rendered in half.

I would suggest you give it another look.

[Mr_sukebe]

7 hours ago, Gunfreak said:

I have an i9 9900k, 3090, and 64 gig ram, it's perfectly reasonable to expect me to be able to play official missions released  by ED at full scale.

Open xr har zero effect for me and it just way more trouble for what it's worth.

How many more people do you want have tell you that your expectations are simply NOT going to be met.

it’s worth bearing in mind that some of the visual options exist to future proof the system, ie can be turned on WHEN our PCs have the grunt to deal with the requirements.

As for not wanting to use OpenXR, that’s just cutting your own nose to spite your face.  There’s a very good guide on the forums to follow.  If you really can’t be bothered, probably worth going for a walk to cool off.

 

[Gunfreak]

12 minutes ago, trevoC said:

I don't think it is reasonable to expect VR to perform top notch yet at higher resolutions or settings. VR is relatively new and doubles the draw calls on an already demanding game. I think VR users need to have more reasonable expectations. By no means would playing this in 4k or 1440p be difficult.

Secondly, not sure how OpenXR is too much trouble for an effective doubling of fps. You literally need to copy one file over to the DCS directory for it to work and then enable one of the presets in game. If implemented properly (file copied) it would be impossible for this not to have an effect as it would cut the required resources to be rendered in half.

I would suggest you give it another look.

As i said it gave me zero advantages. All it does for me is that I now have to start various open xr silliness and if I want to change between vr and flat(which I often do because I capture tracks or work in mission editor) I have to go into vr options and select or deselect vr in dcs. Instead of just starting the game in steam vr. Openxr is graphical since my problem isn't graphical but CPU, open xr does nothing.