Map Performance

[Biggus]

I did end up buying Kola and it's brilliant.  No issues.

SA is far prettier though IMO.  Hopefully one day the sub 900ft performance issue will be fixed.

[Biggus]

So I've just installed a 9070XT after having a 3070 since release.

I'll need to test more, but just in the first Phantom free flight mission, I took her down to below the stutter threshold.  I immediately saw the frames take a nose dive.  50fps, which is probably about 5fps more than the old GPU at that point.  Just as I was beginning to curse my luck, the framerate increased.  I assume that it had a few moments where it needed to build some shaders and then I was back to ~120fps.  Will see how it plays out over the next few days.  I've had posts in this thread before when I thought I'd found a fix and it turned out to be a false hope.

[Joe1978]

I am pleased that you are able to utilize it now.

With the 4080S, I can feel/observe the "step" at 900 feet. It is not as pronounced, nor does it cause a significant FPS drop, but the transition remains noticeable, despite the developer's denial. 

Where I do still notice a very hard jerk is when I try to approach the carrier: for a few seconds the stuttering and jerking is brutal.

 

[Biggus]

8 hours ago, Joe1978 said:

Where I do still notice a very hard jerk is when I try to approach the carrier: for a few seconds the stuttering and jerking is brutal.

Just in the SA map?  I tended to get that on every map with the old GPU.  I haven't tested it yet with the new one.  My coping strategy was to make sure I did a proper case 1 so I'd be close enough to the boat to load the textures so I wouldn't get the stutter during the actual recovery.  I also found a script that changed all the ridiculously large textures to smaller ones so I wasn't getting a big VRAM overflow in situations like that.

I've had a few more flights on the SA map now and I've turned a few things up like forest and scenery details, clutter, some of the shadow options.  I probably see the same number of fps cut off on average, but it's not anywhere near as noticeable at 120fps as it is at 60fps.

I still don't think it's necessarily a hardware issue given there are 4090 users that have reported suffering from it, but I think there might be combinations of hardware, drivers, background processes and the like that might be the killer here.  I might have just been very lucky.

[Joe1978]

hace 6 horas, Biggus dijo:

Just in the SA map? 

Yes. Only in this map. In my case (tomcat), it's the worst-case scenario. 

Overall, my experience with the 4080S is much better. But as I said, I still notice that change at 900", although subtle at times, it's still present.

 

[Biggus]

Just adding because I'm seeing some odd behavior when enabling AFMF and Super Resolution in the AMD software.  It takes a big hit in frames from 900ft down, just like the 3070 did.  Running vanilla MSAAx4, there's a tiny drop but it's barely noticeable.  I'll experiment with Optiscaler too over the next few days just for the hell of it.

[Raven (Elysian Angel)]

I just did a helicopter flight again on the Malvinas, and yes the 900ft performance hit is still there. For me it's actually 950ft AGL: framerate at 949ft is half of that at 950ft.
On the Kola map I have been flying helicopters just fine without this weird fps jump...

[NineLine]

Thanks all, will investigate this 900ish AGL performance hit. 

[NineLine]

Can someone supply me with a short basic track where this happens? I am not seeing a switch at any specific altitude, but of course shadows are very impactful. So I am not sure I am viewing as I should. Thanks!

[TOViper]

Hey Nineline, good morning!

This topic contains also some little information about the 900 feet issue, but it doesn't show any new knowledge.

After work I will try to produce a track file, and at the same time record it as MP4 to share it on YT.

 

[Joe1978]

Thanks NineLine, we've been dealing with this issue for several years (and the developer has been looking the other way). If you look around here, you'll see several threads related to this issue. Tonight I'll try to record a track with the Supercarrier and Tomcat. 

[Mr_sukebe]

Just been out over the Falklands.  Low level in the Harrier.  Looked stunning.  No 900' issue for me.  Nearly constant 72fps in VR, the only exception being during startup at Port Stanley, when it was mid-high 60s.

[Raven (Elysian Angel)]

I took out an Apache again over Port Stanley, and I couldn't reproduce it either. Since I experienced it last time, there have been new releases of graphics drivers, chipset drivers AND a new BIOS so perhaps that either fixed it or somehow a BIOS option got changed so the issue no longer gets triggered 

I don't know... I'll keep an eye on it.

[Mr_sukebe]

Looks like we're probably good then.

[Raven (Elysian Angel)]

1 minute ago, Mr_sukebe said:

Looks like we're probably good then.

Famous last words! 

[NineLine]

Yeah I am not really seeing it either, BUT that doesn't mean its not happening, so if someone can reproduce, please post a track, and I will see if I can see it on my system. But as always make sure everything is up to date, clean out shaders, etc. 

[buur]

also never noticed this 900 feet problem. For me the map is very fluent.

[Mr_sukebe]

The map definitely did have an issue, but seems to have been resolved late last year.

[Biggus]

It was still happening for me in the last patch.  I haven't tested since then, I'll try and grab a track soon.  I don't believe it's very widespread at all and would be surprised if it could be replicated given that people reporting it used a pretty wide range of hardware.

[BlowTorch005]

On 5/14/2025 at 7:38 PM, NineLine said:

Yeah I am not really seeing it either, BUT that doesn't mean its not happening, so if someone can reproduce, please post a track, and I will see if I can see it on my system. But as always make sure everything is up to date, clean out shaders, etc. 

Alright, did a quick flight to check if it was still happening and the answer is yes.

Here is a track, a short 1 min flight going above and under the 750-900ft sgl where the FPS drop happens.

My PC is kinda average for DCS, so the effect may be more pronounced, but it goes from the 60fps limit down to 15.   

Can do more testing if needed, I'm eager to use this map the way it deserves.

South Atlantic low level FPS drops.trk

Edited May 15 by BlowTorch005

[DimSim]

Just for interest, I flew Ground Pounder's excellent free Harrier demo campaign for South Atlantic.

A lot of flying was low altitude (~150ft).

I experienced intermittent but fairly extreme slow downs at times. Because they did not persist, I didn't associate them with specific altitudes or interaction regimes. 

All flight was around the Falklands, not the main land.

I have 32GB RAM and otherwise high system speck.

[Biggus]

Here's a quick demo with my current setup.  FPS limiter set to 65fps, but the effect is still the same.
Behavior is identical with all modules.  I'm using some mods in this track to change the trees from high to low and I'm also using reduced texture sizes and don't really have the patience to return to a completely stock install for this test, because the result is the same.

 

SA_frame_drop.trk

Edit:  My rig is a 5800X on a B450M PRO VDH Max board with 64GB at 3600, a 9070XT and DCS is installed on an M.2 drive.  The issue also existed with a 3070.  Current texture mods include resizing everything above 4096x4096 and replacing the high trees with low tree models.  These mods do not seem to mitigate it.

If I find time, or end up being sufficiently annoyed by this bug enough to make time when I can, I'll return to a standard setup and post more videos and tracks, but it feels utterly pointless because I suspect that it's something that only hits a tiny percentage of the user base.

Edited May 16 by Biggus
Adding hardware

[Czar66]

6 hours ago, Biggus said:

Here's a quick demo with my current setup.  FPS limiter set to 65fps, but the effect is still the same.
Behavior is identical with all modules.  I'm using some mods in this track to change the trees from high to low and I'm also using reduced texture sizes and don't really have the patience to return to a completely stock install for this test, because the result is the same.

 

SA_frame_drop.trk 1.56 MB · 1 download

I'm having the same issues as of late. I did post on this thread (I think) extensive tests and videos showing the problem. GPU load goes bananas bellow a hard AGL altitude which is around 900ft.

Late posts pointed at VRAM load although I have a 12gb VRAM card. I've let this problem go then... It got better after the VRAM usage dcs core update or it was a placebo effect as the problem is intermittent.

Lately the issue came back and wasted me a 40 minute mission on the F-4E. It is like pushing on the brakes on DCS enjoyment even though I have other maps to enjoy, this one is a recent purchase.

I don't really see as a hardware limitation issue as 12gb of VRAM should be very well enough to handle this map, as it handles all others well...

New cards are coming with less than 12gb VRAM and a lot of more reports are going to come about this if the developer doesn't do something.

For me, it is a bug, being otimization or not. Absolutely it should be given of the highest priority to fix because it wrecks frame times inducing a giant amount of lag on commands especially head tracking.

Reducing textures settings is a NO GO. Other maps are fine and reducing textures will result in unusable cockpit on modules such as the Huey and similar aged. I don't plan to be changing settings every time prior to launch a mission either.

Dissapointed about this, as the map is glorious on its own strenghts....

22 hours ago, BlowTorch005 said:

Alright, did a quick flight to check if it was still happening and the answer is yes.

Here is a track, a short 1 min flight going above and under the 750-900ft sgl where the FPS drop happens.

My PC is kinda average for DCS, so the effect may be more pronounced, but it goes from the 60fps limit down to 15.   

Can do more testing if needed, I'm eager to use this map the way it deserves.

South Atlantic low level FPS drops.trk 418.18 kB · 1 download

I'm experiencing similar results here too.

[Biggus]

I will add my hardware to my last post, although based upon seeing users with 4090s experiencing the same thing, I'm doubtful that it's a GPU issue.

[Mr_sukebe]

Have you chaps done the usual DCS housekeeping an optimising to avoid unnecessary use of VRAM (eg disabling the Oculus home)?

If not, could I please suggest you take a scan here: