Huge FPS drop when using lights!

[Mnemonic]

Hello guys, I experience unbearable FPS drop when turning on full illumination on A-10C. Maybe somebody knows what to tweak to get rid of this problem.

 

In order to have clean test bench I uninstalled DCS World completely, and re-installed it from scratch from new 1.2.6 installer. Plus on top I installed only one module which is DCS A-10C. I measure FPS using Fraps.

 

Currently I have a following hardware - DELL XPS L702X laptop:

- i7-2670QM @ 2.2 GHz (3.1 max turbo)

- 8GB RAM

- GeForce GT 555M, 3GB VRAM

- nVidia drivers version - 320.18

- 512 GB SSD (where I have DCS World installed)

- 1920 x 1080 display

- just in case - connected periphery: HOTAS Warthog + Simped F-16 USB Rudder Pedals + Thrustmaster Cougar MFDs + TrackIR5

 

I created a simple mission with runway start of A-10C from Batumi at 6:00 in the summer morning.

 

Here are the settings I used for this test (I also tried to lower down resolution, textures, scenes, but it really doesn't matter in this case, situation with lights is the same):

 

 

In nVidia control panel I disabled AA, or anything which could influence performance (again it doesn't matter and doesn't influence FPS drop).

 

20 FPS in cockpit, looking forward with external illumination turned off (in fact it's about 25)

 

 

external view - 40 FPS, with external illumination turned off

 

 

Pinky switch down - 30 FPS:

 

 

Pinky switch UP - 19 FPS

 

 

I found this ridiculous. So I tried different things, and what helps is in "options.lua"

To set - ["lights"] = 1 instead of ["lights"] = 2

 

This removes actual lighting from illumination devices, but keeps FPS on external views on 50 (within described conditions), doesn't matter if you turn them on or off.

 

BUT

 

It leads to another significant bug - if you have lights=1, and you have UH-1 on map and he shoots minigun - DCS crashes.

 

I would be really helpful if somebody knows how to fix this problem, thanks.

Also would be great if ED programmers will notice this significant issue and fix it as-well.

 

I still can fly daylight missions with awesome FPS of 30-40 but it is total garbage at night, which is very disappointing. I understand that my hardware isn't top notch, but I don't have any issue with performance playing any other modern game on high settings. So I not really convinced to invest money into new PC.

 

P.S. Also, before reinstalling I tried to edit omnidirectional and spot light HLSL shaders, removing all math from it, so they in fact didn't do anyhting - visually there was no lighting but I still had same FPS drop, so I think this is not videocard issue at all, there is probably bug somewhere in the illumination system itself which leads to such result. But I am not sure.

[roadrabbit]

;) Looking at your rig, may I suggest the answer could be just a lack of RAM?

 

This has been discussed in depth elsewhere on the forum, but anything less than 16 GB of RAM causes problems with various parts of DCS World in the latest releases. You only have 8 GB RAM which others have suggest is just not enough. With an Intel i-7 chip and an SSD drive it is only your RAM which gives cause for concern. It costs, yes, but with my rig I have Windows 7 Professional and 24 GB usable RAM (yes - it is a little over the top :D) but I get 80 fps all the time running with three monitors and Track IR5. I also have the nVidia GTX 590 which runs the three monitors as a single screen.

 

Note that to increase usable RAM above 16 GB you will need Windows 7 Professional or above.

Edited October 6, 2013 by roadrabbit
Additional information

[BTTW-DratsaB]

The 10FPS loss with lights on or off is a problem with the graphics engine, it has been like this forever. The A10 cockpit flood light also costs a ton of FPS as well as nav lights.

 

When we eventually get EDGE, hopefully it will be fixed. It is an annoying bug to have in this day. Such minor graphical effects shouldn't cause even a GFX card from 6 years ago to break a sweat.

[Kegetys]

I believe this happens because of the way lights are implemented, all geometry lit by the light appears to be drawn for a second time (or more if there is more lights). That combined with badly optimized models results in huge amount of draw calls and everything is bottlenecked by the cpu not being able to push draw calls to the gpu fast enough. Its especially a problem with D3D 9 where every draw call is relatively expensive.

[Mnemonic]

Thanks guys for your suggestions!

 

This has been discussed in depth elsewhere on the forum, but anything less than 16 GB of RAM causes problems with various parts of DCS World in the latest releases. You only have 8 GB RAM which others have suggest is just not enough.

Is it true? I thought 8 GB should be enough for DCS, here is a screens from Task Manager, with DCS running:

 

 

 

The 10FPS loss with lights on or off is a problem with the graphics engine, it has been like this forever. The A10 cockpit flood light also costs a ton of FPS as well as nav lights.

 

It is indeed true. For me it was like this all the time, but I decided to ask here maybe somebody have a solution for this, some kind of mod, or tweak, because it is extremely annoying.

 

When we eventually get EDGE, hopefully it will be fixed. It is an annoying bug to have in this day. Such minor graphical effects shouldn't cause even a GFX card from 6 years ago to break a sweat.

 

I hope EDGE will fix things, and eventually I don't need to change my hardware to boost FPS in DCS, but now I have some doubts.

 

I believe this happens because of the way lights are implemented, all geometry lit by the light appears to be drawn for a second time (or more if there is more lights). That combined with badly optimized models results in huge amount of draw calls and everything is bottlenecked by the cpu not being able to push draw calls to the gpu fast enough. Its especially a problem with D3D 9 where every draw call is relatively expensive.

 

That's what I thought, but isn't there any mod that could remove this huge load? Shader replacement, or other sort of tweaking we could do now, without new engine?

[Kegetys]

That's what I thought, but isn't there any mod that could remove this huge load? Shader replacement, or other sort of tweaking we could do now, without new engine?

 

Well, I guess you could remove the lights. But maybe easier is to just turn them off :) I doubt modifying the shaders would help that much except in special cases. Modifying models so they would be better optimized (proper lod levels, optimized for minimal draw calls) would maybe help but I guess that is a huge task. Better to just wait for EDGE maybe.

[kk0425]

;) Looking at your rig, may I suggest the answer could be just a lack of RAM?

 

This has been discussed in depth elsewhere on the forum, but anything less than 16 GB of RAM causes problems with various parts of DCS World in the latest releases. You only have 8 GB RAM which others have suggest is just not enough. With an Intel i-7 chip and an SSD drive it is only your RAM which gives cause for concern. It costs, yes, but with my rig I have Windows 7 Professional and 24 GB usable RAM (yes - it is a little over the top :D) but I get 80 fps all the time running with three monitors and Track IR5. I also have the nVidia GTX 590 which runs the three monitors as a single screen.

 

Note that to increase usable RAM above 16 GB you will need Windows 7 Professional or above.

 

I have 8 GB and it runs fine for me. Could you provide a link or discussion saying that 8 GB isn't enough, because I haven't read that anywhere. Looking at OP's set up I would guess it's the GPU, being a 555M I would guess his FPS drop would be due to his weaker GPU.

 

My rig is a Phenom II X4 965 BE, 8 GB RAM, EVGA factory OC'ed 570 GTX, and a Samsung 840 pro SSD. I typically get about 40-60 FPS depending on how many objects I'm looking at in the mission.

[Mnemonic]

I typically get about 40-60 FPS depending on how many objects I'm looking at in the mission.

Do you have 60 FPS with lights on?

 

I have 30-50 FPS typically, if I don't use lights, if I use them it's 15-20 less.

Also, I am pretty sure that with lights=1 in options.lua, UH-1 miniguns shouldn't crash DCS, and it is a bug, which devs should fix!

 

GeForce GT 555M isn't powerful GPU, but it's enough to run DCS with daylight conditions on 30 FPS in high settings, why should external lights drop it so much? (I know that it looks like that implementation is poor)

Also I play other modern games on same rig, which run just perfectly fine on 555M.

Edited October 6, 2013 by Mnemonic

[Mnemonic]

I completely agree that GeForce GT555M is not very fast by todays standards, true.

But I don't have any problems with Su-25T or Ka-50 aswell, the thing is on A-10C there are many lights, and the small ones on top cause about 10-12 FPS drop. Also same effect with floodlights on A-10C.

 

And scenes, AA or render-to-texture size have nothing to do with it.

Question is - can I tweak something in DCS World to make this FPS drop less significant, or remove it completely.

When I play singleplayer I can turn off lights, but it is stupid to ask other people to do that during multiplayer session.

 

Also GeForce 555M doesn't have shared memory, it is dedicated mobile videocard and it uses it's own 3 Gigs of VRAM. And it is faster than GT 460M.

When it comes to modern games like Battlefield3, Dishonored, Crysis2, Metro Last Light, and even ARMA3 - runs just fine with it, of course not maxed out but on pretty high settings.

Edited October 6, 2013 by Mnemonic

[Mnemonic]

GeForce GT 555M is not a very fast GPU.

A 4 year old GTX 285 is 2x faster... Screenshot with 45FPS and Shkval on Sochi is attached.

Here, everything on max, except water, mirrors, and shadows: 48FPS with GeForce 555M

 

 

So, sorry I don't think your point is valid. Su-25T is very resource lightweight comparing to A-10C. Speaking of which I also don't have a problem to fly, except when I turn on external light, that's why I created a topic in first place.

[LexiconG2]

Your system is so very much on the low end as far as GPU that its not really a valid complaint in most cases however if you look at my spec. DCS world still have issues with Cluster bombs, explosions, and other items that are not and should not be slowing down more then 2-4 FPS. DCS world and it's engine is basically a well used piece of junk. It does not use multi-threading or a GPU in a modern intelligent way. ED/DCS know this and that is why they have been developing EDGE for such a long time. For now performance and DCS is just a fact of it's existence. If DCS was using a GPU your system would not be getting 16FPS it's your CPU thats getting your FPS. You are also using a laptop which is not good for PC gaming in general mainly due to power limitations, voltages and overall engineering limits.

Edited October 6, 2013 by LexiconG2

[Mnemonic]

Hey LexiconG2, I know that I have "low specs" but I willing to set lighting calculation to something more simple (like lighting=1 in options.lua), the thing is since Huey release, I can't because I have crash the moment Huey fires miniguns.

And except of lighting I have very nice FPS - 30 to 40 during flight and fight. So I don't think the specs are too low that my requests are not valid.

 

Everybody suffers from cluster bombs, I'm well aware of it, but come on, external lights? This really annoying. Every time I happen to notice that I'm willing just close DCS and go fly Falcon BMS instead, where I have stable 60 FPS under any conditions, with lights or without, with any amount of ground and air forces, and with any type of ammunition.

 

I was expecting that there are some FPS tweaks which cure the damn lights, but apparently there are none.

[Nate--IRL--]

I'm not sure is "Lights=1" is a supported feature, but the crash has been reported anyway.

 

Nate

[LexiconG2]

Hey LexiconG2, I know that I have "low specs" but I willing to set lighting calculation to something more simple (like lighting=1 in options.lua), the thing is since Huey release, I can't because I have crash the moment Huey fires miniguns.

And except of lighting I have very nice FPS - 30 to 40 during flight and fight. So I don't think the specs are too low that my requests are not valid.

 

Everybody suffers from cluster bombs, I'm well aware of it, but come on, external lights? This really annoying. Every time I happen to notice that I'm willing just close DCS and go fly Falcon BMS instead, where I have stable 60 FPS under any conditions, with lights or without, with any amount of ground and air forces, and with any type of ammunition.

 

I was expecting that there are some FPS tweaks which cure the damn lights, but apparently there are none.

 

The best explanation is that I also have issue with FPS and lighting and even just external lighting seems to have an effect on performance. Please be aware that EDGE is just on the horizon for DCS World I can feel it in my bones. With this new engine these flaw I hope will not exist. DCS/ED have had a lot to learn during the DCS project. Thats really what the issue is. The current engine won't be here for another 6 months so best bet is just to hang tight.

[Mnemonic]

I'm not sure is "Lights=1" is a supported feature, but the crash has been reported anyway.

 

Nate

Thanks! Good to know ED knows about it. I think Lights=1 was in the settings menu, long time ago, in a galaxy far away, in the settings of first flaming cliffs, but it worked fine until UH-1.

 

The best explanation is that I also have issue with FPS and lighting and even just external lighting seems to have an effect on performance. Please be aware that EDGE is just on the horizon for DCS World I can feel it in my bones. With this new engine these flaw I hope will not exist. DCS/ED have had a lot to learn during the DCS project. Thats really what the issue is. The current engine won't be here for another 6 months so best bet is just to hang tight.

 

Yes indeed, one of the reasons I hesitate with investing money into new machine - I don't know how much resources will EDGE, consume, I hope it would be much faster than current gen engine, and I will not need to upgrade at all. And If not - at least I will know what machine to buy by then.

[kk0425]

Do you have 60 FPS with lights on?

 

I have 30-50 FPS typically, if I don't use lights, if I use them it's 15-20 less.

Also, I am pretty sure that with lights=1 in options.lua, UH-1 miniguns shouldn't crash DCS, and it is a bug, which devs should fix!

 

GeForce GT 555M isn't powerful GPU, but it's enough to run DCS with daylight conditions on 30 FPS in high settings, why should external lights drop it so much? (I know that it looks like that implementation is poor)

Also I play other modern games on same rig, which run just perfectly fine on 555M.

 

Not sure why lights affect you so much. I don't notice a difference with lights on or off. Can only guess is has something to do with dynamic shadows, but if you already had those turned off then I have no idea.

[=Mac=]

;) with my rig I have Windows 7 Professional and 24 GB usable RAM (yes - it is a little over the top :D) but I get 80 fps all the time running with three monitors and Track IR5. I also have the nVidia GTX 590 which runs the three monitors as a single screen.

 

Note that to increase usable RAM above 16 GB you will need Windows 7 Professional or above.

 

Please check my gaming computer's specs. I run Win 7 64 bit with, normally, just one screen (my preference) and can only get 50 fps around cities. If I run three screens (no MFCD mode) my FPS drops to the upper teens. How do you get the 80's?

Edited October 6, 2013 by =Mac=

[Mnemonic]

Not sure why lights affect you so much. I don't notice a difference with lights on or off. Can only guess is has something to do with dynamic shadows, but if you already had those turned off then I have no idea.

 

I have severe lighting FPS issue only on A-10C and also on UH-1H but I don't fly it much currently. Flaming Cliffs crafts and Ka-50 are ok. I think it has to do with high-poly models and amount of light sources. Btw usually I also turn on shadows, they lower the FPS a bit on my setup, but not much. I turned them off now, for testing reasons.

 

You don't notice the difference on A-10C? Or other aircrafts?

[SkateZilla]

Hello guys, I experience unbearable FPS drop when turning on full illumination on A-10C. Maybe somebody knows what to tweak to get rid of this problem.

 

In order to have clean test bench I uninstalled DCS World completely, and re-installed it from scratch from new 1.2.6 installer. Plus on top I installed only one module which is DCS A-10C. I measure FPS using Fraps.

 

A GTX550 isnt that powerful, then add in the fact that it's (the Mobile Version) is undervolted and downclocked to save power and Heat, makes it even weaker.

 

Turning on Full Illumination basically forces the shaders to do alot more work, It's Adding another Light Point to the world.

Some surfaces are more reflective than others, as well as having to render shadowing for the new light point (if enabled) and reflective textures, specular textures, etc etc etc.

 

The 3D Cockpit Alone is 210,265 Triangles.

Edited October 7, 2013 by SkateZilla

[Mnemonic]

I have a GT 555 it is much more powerful than 550.

Paradox is that I've tried to remove all the math from omnidirectional and spot lights in hlsl shaders, and still got the same fps drop, even when light shaders didn't do anything. So it does look like drawcall problem, and not how heavy are actual shaders.

 

Again, in daylight conditions, without external illumination, I have decent FPS.

Edited October 7, 2013 by Mnemonic

[kk0425]

I have severe lighting FPS issue only on A-10C and also on UH-1H but I don't fly it much currently. Flaming Cliffs crafts and Ka-50 are ok. I think it has to do with high-poly models and amount of light sources. Btw usually I also turn on shadows, they lower the FPS a bit on my setup, but not much. I turned them off now, for testing reasons.

 

You don't notice the difference on A-10C? Or other aircrafts?

 

Yeah, that's about all I've got. The high poly count with the different lighting sources is probably causing it in the highly detailed cockpits. But no, I don't see any difference. I'm guessing optimization is low on ED's priority list right now since EDGE will be released soon. No idea if it will help with cockpit rendering performance but we can only hope right now.

[SkateZilla]

I have a GT 555 it is much more powerful than 550.

Paradox is that I've tried to remove all the math from omnidirectional and spot lights in hlsl shaders, and still got the same fps drop, even when light shaders didn't do anything. So it does look like drawcall problem, and not how heavy are actual shaders.

 

Again, in daylight conditions, without external illumination, I have decent FPS.

 

144 Cuda Cores is on the LOW END of the Entry Level Spectrum and Tier 14 of the Overall Performance Charts.

 

The GT555M Used on DELL XPS L702X Systems is the 1GB GDDR3 Version, Which Drops it to Tier 15.

 

My 7 Year Old eVGA 8800GTS SSC has more power than your GT555M

 

Turn Textures and Scenes down to LOW. With Only 1 GB of GDDR VRAM you shouldnt have that on HIGH, and with 144 Cuda Cores, Scenes Shouldnt be on High either.

 

Visible Range Could Also be lower.

Edited October 7, 2013 by SkateZilla

[Mnemonic]

144 Cuda Cores is on the LOW END of the Entry Level Spectrum and Tier 14 of the Overall Performance Charts.

Ok, so what.

 

 

The GT555M Used on DELL XPS L702X Systems is the 1GB GDDR3 Version, Which Drops it to Tier 15.

I have a version with 3GB VRAM

 

My 7 Year Old eVGA 8800GTS SSC has more power than your GT555M

Not true, my old machine have GeForce GTS 9800, and it performs much worse in DCS.

 

Turn Textures and Scenes down to LOW. With Only 1 GB of GDDR VRAM you shouldnt have that on HIGH, and with 144 Cuda Cores, Scenes Shouldnt be on High either.

 

Visible Range Could Also be lower.

With 3 gigs of VRAM it doesn't matter I have textures on low or high, also if I lover the resolution it doesn't influence much.

Are you kidding me? I show you a screenshots where I easily have 30 - 40 fps with high scenes and high distance. Why should I lower them? I tried everything on low, but I still have FPS drop of 12-20 on turning external lights on A-10C.

[SkateZilla]

The Problem is Texture Bandwidth and Raw Rendering Power, that Card, to put nicely, Lacks that.

 

You can Run Smoothly with stuff turned off, and when you turn it on, boom, FPS Drops.

 

The 555m has 144 cores, running anywhere between 200 to 300MHz Lower than the desktop counterparts.

And Shader Cores running anywhere between 200-500Mhz lower then desktop counterparts.

 

The 555m In the Dell Machines is GDDR3, so while it has 3 Memory Channels and More Memory,

the Memory is Slower than 1GB and 2GB GDDR5 Counterparts found in other Manufacturers.

 

Slower Video Memory causes a FPS Hit when Loading A lot of Textures.

-Thus My Recommendation to Lower Textures, Smaller Textures load faster.

 

Slower CUDA Cores, and Alot Less of them, Causes a FPS Hit, when there's Alot of Geometry On Screen.

-Thus My Recommendations to Lower Scenes and Visibility Range.

 

High Visibility Range Renders Objects further from the Aircraft, Your GPU Simply doesnt have the power to Render everything.

 

 

It's a Give or take process.

 

IF you watch the CPU Core DCS is Running on, the Only way to confirm it's a DX9c Draw Call issue is the look at the Overhead on the CPU Core, if the Core is Pegged at 100% and the GPU Usage Drops to 50-75% during the FPS Drop ingame, then it's a DX9C Draw Call issue.

 

Simply Turning on a Light shouldnt Overhead the DX9C Draw Calls that Much.

 

 

 

And Yes,

My eVGA 8800GTS SSC 640MB 320-Bit (112 SP) @ 625 Core/1500 Shaders Gets Better Benchmarks than all Versions of the GT555M.

(Then Again it gets better benches than the 8800GTX Ultra As well.)

Edited October 7, 2013 by SkateZilla

[Cnuke]

I remember someone made a "mod" by editing out some light sources.

I re-produced the edit..

 

Can you make a backup of Lights.lua found here:

C:\Program Files\Eagle Dynamics\DCS World\Scripts\Aircrafts\_Common

And try if you have a better fps with this:

Lights.rar

I should try it first for you but unfortunately I can't until about 5 hours later today^^

Edited October 7, 2013 by Cnuke