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WebMaximus

99% GPU load at dusk in overcast conditions=stutters

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Overall my performance is really good but one thing I noticed is that if I fly at dusk and there's overcast conditions and I'm above the clouds my GPU load is pinned at 99% and I get pretty bad stuttering. By the time I get lower and almost start descending through the clouds the load decreases and the stuttering issue goes away. I've never experienced this issue when flying under the same conditions but during daytime.

 

I'm using REX Soft Clouds (DX5) and I've tried reducing both the CDD as well as the max upper visibility settings in ASN but to no avail. I've also tried removing some of the shadow options in P3D but still to no avail. I need to find some way to ease off some of the burden on my GPU and I also need to figure out why this only happens when flying at dusk (and possibly also dawn) and not when flying during daytime.

 

Up until now I've been using FIBER_FRAME_TIME_FRACTION=0.01 but I think I'm gonna try to remove this "tweak" and see what happens. IIRC having this set too low can cause the GPU to be swamped under certain conditions. However removing it (or increasing the value) can instead decrease your overall performance so I guess this like many other things will be a balance act trying to find what value works best. If this will even help addressing my issue in the first place, maybe it not related at all to the kind of issue I have.

 

Anyone else seen this performance issue or even better knows how to fix it? Guess one easy workaround is to only fly during daytime :wink:

 

My hardware setup is a 4470K@4.5GHz and a 980 Ti@1455MHz running P3Dv2.5 on a single 4K screen.

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Have same cpu and gpu with a iiyama monitor @ 2560x1440  ( frames set at 60),  cpu @ 4.4,   no o/c on gpu.
 
test over Washington state with ASN sp3 and Rex soft clouds at dusk.
 
gpu temp 57deg
memory load 1872
gpu load 56%
vas 1138572  ( note only after a few mins )
after a lot of messing around decided to try these .cfg settings I found on the web.

[JOBSCHEDULER]
AffinityMask=252
[bufferPools]
UsePools=1
PoolSize=900000000 ( I know it looks high but have ago anyway)

 

no FFTF

don't seem able to get the memory load above 2350 mb, have tried usepools=0 and lower poolsize .

no idea to the relationship between gpu load and memory load.

 

bob

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I have been playing with monitoring tools for the last couple of days and noticed as my screen is 60 Hrtz, if i lock my frames at 32 (thank you VIC) it drops the usage and the heat of the GPU,  also takes the load of the CPU.  But then again looking at your specs,  there a hell of a lot more powerful then mine,  so i don't know if that would help 

 

 


My hardware setup is a 4470K@4.5GHz and a 980 Ti@1455MHz running P3Dv2.5 on a single 4K screen.

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Richard,

 

Try these settings within ASN

[Cloud options]
PreventTstormsWithCB=1
MinimumCloudDrawDistance=120
MaximumCloudDrawDistance=140
EnhanceIMCConditions=1
HighDetailCBs=1
MaximumCloudLayers=3
[...]
[Visibility options]
MaximumVisibilitySM=15
MaximumUpperVisibilitySM=63
[...]
 
And these settings in Prepar3D.cfg under [Display]
[Display]
[...]
TEXTURE_FILTERING=4
MSAA=4
SSAA=0
VSYNC=1
FXAA=0
TRIPLE_BUFFER=1
TEXTURE_BANDWIDTH_MULT=30
UPPER_FRAMERATE_LIMIT=30
[...]
 
 
Also, pay a visit to NvidiaInspector and delete P3D.exe profile off the list (after a profile backup of course).
If that makes your day, only then, gradually increase cloud layers in ASN from 3 to 8 when cruising in flight levels above overcast, to find the sweetspot.
 
 
Hope this helps.

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Thanks for your input guys, will play around a bit with different settings suggested and see what I end up with.

 

I guess what makes me most puzzled is why I don't see this problem when flying during daytime, it's like the combination of dense clouds and dusk makes my GPU go crazy.

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Looking at the settings in P3D, what would you say are the most GPU-intensive settings?

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Dusk and Dawn have always been heavy on GPU and VAS ... that's another reason I do a lot of testing at those times.  Some things you can try:

 

1.  If you have building and cloud shadows enabled you try adjusting these values in the Prepar3d.cfg:

 

GROUND_SHADOW_TEXTURE_SIZE=1024  (or even 512)
CLOUD_SHADOW_TEXTURE_SIZE=512
 
2.  Reduce cloud density to Medium
 
3.  Reduce AA  (if you're using SGSS AA via NI disable it)
 
4.  Reduce cloud draw distance to 80mi
 
Cheers, Rob.

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Yup - dawn/dusk has always been problematical in both FSX and P3D.

 

 

Vic

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I wonder why that is that dusk and dawn are so hard on the GPU? I would like to think the only difference is another kind of light and other colors but guess it's not that easy.

 

Looks like I might have fixed the issue by disabling all shadows but the internal and external ones and I also decreased the quality from high to medium.

 

I'm not using NI at all anymore and especially not SGSS since I learned by now that is THE performance killer nr 1 when entering dense clouds. Luckily I don't suffer that much from bad AA anymore after replacing my 1080 screen with a 4K TV :wink:

 

I like to keep the CDD in ASN (both min and max) at 110 since the default max upper visibility is set to 100. This to avoid seeing how the clouds are drawn ahead of me. Did try to temporarily reduce the CDD while I was troubleshooting my performance issue but didn't see much of an improvement.

 

Will do some more testing to make sure I nailed the issue using my current settings.

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I wonder why that is that dusk and dawn are so hard on the GPU? I would like to think the only difference is another kind of light and other colors but guess it's not that easy.

 

Could be that the sim is attempting to display what is not visible to the naked eye. Perhaps what we need is a sky or weather engine that provides variable detail in terms of what is realistic in regard to human vision, and altitude based visibility distance. 

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2 things that helped me

 

1. In nvidea control panel enable "single diplay"  in Multi/mixed gpu acceleration (if you have 1 screen)

2. set frames to unlimited

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Could be that the sim is attempting to display what is not visible to the naked eye. Perhaps what we need is a sky or weather engine that provides variable detail in terms of what is realistic in regard to human vision, and altitude based visibility distance.

Yes, maybe you're right and if the sim indeed is trying to achieve things that we still can't see that of course is a real waste of resources.

2 things that helped me

 

1. In nvidea control panel enable "single diplay" in Multi/mixed gpu acceleration (if you have 1 screen)

2. set frames to unlimited

I already have both these settings the way you suggest but thanks anyway!

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I wonder why that is that dusk and dawn are so hard on the GPU?

 

Multiple texture sets are being blended so increases number of render passes ... otherwise it would look very odd (aka not realistic) to see a sudden change from day texture to dawn textures.  Also another GPU load for dawn and dusk is calculation of shadows, the shadows require more complex calculations as the shadows are MUCH longer adjusting more textures from their cast.

 

Cheers, Rob. 

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Uh oh. I'm nervous now. I've got a GTX 980 Ti SC on the way, and I hope it performs well in 4K!

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Uh oh. I'm nervous now. I've got a GTX 980 Ti SC on the way, and I hope it performs well in 4K!

Oh I'm so sorry hun have you not heard, these cards don't perform well at all. Best thing to do is sell it to me (cheap) and get yourself a Titan, probably best:)

 

980ti is a monster of a card

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I am evening thinking of buying a GTX980ti and selling my GTX970......

 

This is to go up to 1440p resolution (not 4k though)

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I did a quick check and did find GWX.exe running but that makes sense considering I did accept the free offer to upgrade to Win10 when available. So in that sense I don't blame MS for having some kind of tool running on my PC to handle this upgrade process both checking for Win10 availability and also download the installation media in the background to make the upgrade faster when time comes to perform the actual upgrade.

 

Interesting info though how much of your resources this tool can consume at times running in the background so now with Win10 being GA I guess I'll just make sure to get the upgrade and run through it once to have my Win7 key converted and I'll also make sure to get the Win10 installation media and I'll then revert back to my Win7 installation until Win10 has shown it's real colors for us P3D users.

 

Back to the main question regarding my performance drop flying at dusk in dense clouds I'm pretty sure GWX was not to blame since it has nothing to do with my GPU load which I clearly could see was pinned at 99% when I experienced the stutters and as soon as I got into and later under the clouds the issue was gone and the GPU load returned to the normal 70-85% or so.

Multiple texture sets are being blended so increases number of render passes ... otherwise it would look very odd (aka not realistic) to see a sudden change from day texture to dawn textures.  Also another GPU load for dawn and dusk is calculation of shadows, the shadows require more complex calculations as the shadows are MUCH longer adjusting more textures from their cast.

 

Cheers, Rob. 

 

Yep, that all makes perfect sense Robert.

Uh oh. I'm nervous now. I've got a GTX 980 Ti SC on the way, and I hope it performs well in 4K!

 

The 980 Ti performs really really good in 4K! Comparing to my old 1st gen Titan it's like night and day.

 

However until the software we're all running (P3D) is rebuilt in one way or the other (new core engine/DX12 compatibility/64-bit etc etc or whatever might happen down the road) I think we will continue to see performance issues in some regard under certain conditions with certains settings pretty much regardless of the hardware used.

 

This has been true for many, many years and I don't think we're by the end of that road yet.

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The 980Ti performance wise is VERY VERY close to a Titan X for all the data I've seen ... but price/performance ratio is the 970 (even at 4K res).

 

As for Windows 10, I've seen claims of 100% performance improvement to 0% performance improvement ... I would probably dare speculate a <5% performance improvement.  Hopefully next week I can dig into some testing of P3D under Win10 ... but there are some key players in my setup that I'm not sure will work (i.e. GoFlight) ... their forums have been down for many weeks now and in the past GoFlight have been less than responsive to Microsoft's new OS versions.

 

Cheers, Rob.

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The 980 Ti performs really really good in 4K! Comparing to my old 1st gen Titan it's like night and day.

 

However until the software we're all running (P3D) is rebuilt in one way or the other (new core engine/DX12 compatibility/64-bit etc etc or whatever might happen down the road) I think we will continue to see performance issues in some regard under certain conditions with certains settings pretty much regardless of the hardware used.

 

This has been true for many, many years and I don't think we're by the end of that road yet.

 

I'm getting around 30 fps, but it's stuttery. What are your display settings? My CPU is similar to yours as well.. 

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Sorry to hear that, very smooth here.

 

What do you mean by display settings, can you be a little bit more specific?

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Sorry to hear that, very smooth here.

 

What do you mean by display settings, can you be a little bit more specific?

Yes, What are your display settings? I'll give them a whirl and see how it goes. Our set-ups are basically identical.

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Yes, What are your display settings? I'll give them a whirl and see how it goes. Our set-ups are basically identical.

 

Here you go

[GRAPHICS]
TEXTURE_MAX_LOAD=1024
NUM_LIGHTS=4
MIPMAP_VC_PANELS=1
TESSELLATION=1
COCKPIT_HIGH_LOD=1
AIRCRAFT_REFLECTIONS=1
LANDING_LIGHTS=1
DAWN_DUSK_SMOOTHING=1
LENSFLARE=0
HDR=1
BLOOM_LEVEL=2
SHADOW_QUALITY=3
TERRAIN_SHADOW_CAST_DISTANCE=3
CLOUD_SHADOW_CAST_DISTANCE=3
OBJECT_SHADOW_CAST_DISTANCE=2
CONTENT_NO_SHADOW=0
INTERIOR_SHADOWS_CAST=1
EXTERIOR_SHADOWS_CAST=1
SIMOBJECT_SHADOWS_CAST=0
TERRAIN_SHADOWS_CAST=1
VEGETATION_SHADOWS_CAST=0
BUILDING_SHADOWS_CAST=0
CLOUD_SHADOWS_CAST=1
INTERIOR_SHADOWS_RECEIVE=1
EXTERIOR_SHADOWS_RECEIVE=1
SIMOBJECT_SHADOWS_RECEIVE=0
TERRAIN_SHADOWS_RECEIVE=1
VEGETATION_SHADOWS_RECEIVE=0
BUILDING_SHADOWS_RECEIVE=0
SHADOW_NUM_CASCADES_LOW=4
SHADOW_NUM_CASCADES_MID=5
SHADOW_NUM_CASCADES_HIGH=7
SHADOW_NUM_CASCADES_ULTRA=12
GROUND_SHADOW_TEXTURE_SIZE=2048
CLOUD_SHADOW_TEXTURE_SIZE=512
SHADOW_LOG_PARTITION_LOW=0.850000
SHADOW_LOG_PARTITION_MID=0.850000
SHADOW_LOG_PARTITION_HIGH=0.850000
SHADOW_LOG_PARTITION_ULTRA=0.850000
EFFECTS_QUALITY=2
EFFECTS_DISTANCE=2
[DISPLAY]
SKINNED_ANIMATIONS=1
TEXTURE_BANDWIDTH_MULT=30
UPPER_FRAMERATE_LIMIT=61
TEXTURE_FILTERING=16
MSAA=4
SSAA=0
FXAA=0
VSYNC=0
TRIPLE_BUFFER=0
WideViewAspect=1
FullScreenExclusive=0
FullScreenAutoFill=1
[PANELS]
PANEL_OPACITY=0
[SCENERY]
IMAGE_COMPLEXITY=5
[TERRAIN]
LOD_RADIUS=4.500000
TESSELLATION_FACTOR=90
MESH_RESOLUTION=25
TEXTURE_RESOLUTION=29
AUTOGEN_VEGETATION_DENSITY=2
AUTOGEN_BUILDING_DENSITY=2
DETAIL_TEXTURE=1
WATER_REFLECT_CLOUDS=0
WATER_REFLECT_USERAIRCRAFT=0
WATER_REFLECT_SIMOBJECTS=0
WATER_REFLECT_TERRAIN=0
WATER_REFLECT_AUTOGEN_VEGETATION=0
WATER_REFLECT_AUTOGEN_BUILDINGS=0
WATER_REFRACT_CLOUDS=0
WATER_REFRACT_USERAIRCRAFT=0
WATER_REFRACT_SIMOBJECTS=0
WATER_REFRACT_TERRAIN=0
WATER_REFRACT_AUTOGEN_VEGETATION=0
WATER_REFRACT_AUTOGEN_BUILDINGS=0
ENABLE_BATHYMETRY=0
WATER_CLARITY=30
WATER_DETAIL=4
[WEATHER]
CLOUD_DRAW_DISTANCE=8
DETAILED_CLOUDS=1
OPTIMIZE_DENSE_CLOUDS=0
CLOUD_COVERAGE_DENSITY=6
THERMAL_VISUALS=0
DownloadWindsAloft=0
DisableTurbulence=0
DynamicWeather=0
VolumetricFog=1
[TrafficManager]
AirlineDensity=0
GADensity=0
FreewayDensity=15
ShipsAndFerriesDensity=15
LeisureBoatsDensity=15
IFROnly=0
AIRPORT_SCENERY_DENSITY=0
[AContain]
ShowLabels=0
ShowUserLabel=0
ShowLabelManufacturer=1
ShowLabelModel=1
ShowLabelTailNumber=0
ShowLabelDistance=1
ShowLabelAltitude=1
ShowLabelAirline=0
ShowLabelAirlineAndFlightNumber=0
ShowLabelFlightPlan=0
ShowLabelContainerId=0
ShowLabelAirspeed=0
ShowLabelHeading=0
LabelDelay=1000
LabelColor=FFFF0000

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Rob is correct. It's the interpolation of the textures during those time periods that contribute.

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