Bug Report: Heat Blur on, reduces GPU and CPU performance

[TZeer]

Issue: With the Heat Blur effect on the A-10C. The CPU and GPU's will throttle down their performance when Heat Blur is active on the A-10C. Any time the plane is flying slower then ^260 knots the GPU and CPU will reduce their performance.

 

Does not happen if the AI is flying the plane. Only when you are the pilot. Does not happen when flying the SU-25T. Do not have the other modules so have not tested them.

 

In my case, the FPS will go down from ~100FPS and to about 50-60 FPS. When heat blur effect goes off, fly faster then ~260 knot, performance on GPU and CPU goes up. It's like there's put a maximum limit of how high the GPU's can go in performance.

 

This is on a SLI setup.

 

 

DxDiag.txt

Performance Drop.trk

[Kuky]

To test this properly and eliminate other facors (other than heatblur) to be cause of FPS hit do the following:

 

Create new missiong with 1 A-10C only and place it on empty parts of the map or over the sea so it's away (at least 150km) from coastline of the georgian part of the map.

 

Turn off FPS limit in Graphics.cfg

 

Fly the A-10C in this mission and turn on FPS counter... note the FPS when heatblur is on and off... and report the FPS values here.

 

PS: you can also attach the mission you made, if under these conditions you still see massive FPS loss, I'll try it out also on my end. Also if you want to compare FPS loss best is not use FPS number but percentages (because if you say you have 10fps loss that's a lot on 30fps but not a lot on 130fps)

[ZaltysZ]

Do you have huge drop when heat blur is rendered or even when it is just supposed to be present (i.e. you fly slow and look at HUD)?

[TZeer]

Did as requested.

 

Here is the GPU and CPU performance while performing the test.

 

Every time the GPU and CPU usage goes down, is when the heatblur effect comes on.

 

This does not happen when the AI is flying the plane and you are just a spectator.

 

FPS goes from 180 and down to 100 during this. And jumps back up again to 180 when heat blur goes away.

 

 

 

Screenshots taken during test. As you can see on the FPS counter the drop is quite high.

 

 

 

 

heatblurtest2.trk

test2.miz

[TZeer]

Just for info, if you combine the FPS drop from the heatblur bug, and the FPS drop you get from the green emergency flood light in the cockpit, you go from 180 FPS and down to 60 FPS..... The green light alone takes you from 180 and down to 100.

[Kuky]

I just tried this on my end (in triple screen setup) and I got in F2 view 56fps down to 51fps when heat blur starts, and in cockpit view I got 40fps down to 37fps. So there is definitely some fps hit, I am confused though why is there fps hit when no heat blur is visible (as in when siting in the pit and looking forwards)????

 

Still not a massive FPS difference that you have (percentage wise), looks to be about 9% on my end. I can't see how you go from 180fps to 101fps?

 

You know what, have you tried turning SLI off and running it with 1 video card?

Edited February 15, 2013 by Kuky

[TZeer]

I just tried this on my end (in triple screen setup) and I got in F2 view 56fps down to 51fps when heat blur starts, and in cockpit view I got 40fps down to 37fps. So there is definitely some fps hit, I am confused though why is there fps hit when no heat blur is visible (as in when siting in the pit and looking forwards)????

 

Still not a massive FPS difference that you have (percentage wise), looks to be about 9% on my end. I can't see how you go from 180fps to 101fps?

 

You know what, have you tried turning SLI off and running it with 1 video card?

 

I have tried running it with 1 card, and as you say, the difference is not as big as in SLI, but with one card the single card is running at 100% even during the drop.

 

I suspect that 1 card simply is not enough to provoke the same drop, due to it being a bottleneck. I guess it's also one of the reasons why it's hard to detect. DCS is not exactly

known to have a stellar performance gain even if you go SLI. And this bug might be the one of the reasons.

 

In more populated areas I go from about 100 FPS and down to 50-60. And since the A-10C rarely go above 260 knots with fuel and fully loaded, this bug is almost always active. And therefor people think SLI doesn't give much performance gain.

 

If you do external view, and zoom out, the effect will go away as well.

 

Then set up an AI flight to go slower then 260 knots, and do the same. And you wil not have the FPS drop.

 

 

Try do a single screen setup and check your FPS.

[SkateZilla]

Sounds more like nVidia needs to make a better SLI Profile for DCSW, as the work load isnt distributed properly. which causes drops in FPS and GPU usuage in your case.

[BIGNEWY]

I don't see the issue if you drop to 50/60 fps, if it dropped below 30 then it would be an issue :)

[cichlidfan]

I see an issue if heat blur (or anything else) is affecting frames when not in the field of view.

I am confused though why is there fps hit when no heat blur is visible (as in when siting in the pit and looking forwards)????

 

[SkateZilla]

Mirrors/Reflection off the canopy.

[TZeer]

Sounds more like nVidia needs to make a better SLI Profile for DCSW, as the work load isnt distributed properly. which causes drops in FPS and GPU usuage in your case.

 

Wrong. SLI works fine. Heat blur on the SU-25T works fine. Heat blur on a AI A-10C works fine.

 

Heat blur on your own A-10C, CPU and GPU takes a dump.

 

I don't see the issue if you drop to 50/60 fps, if it dropped below 30 then it would be an issue

 

It is an issue when you try to run with Vsync @ 60 FPS. And the difference in 30 and 60 FPS is huge when it comes to smoothness in the game.

 

30 FPS with Vsync doesn't look to bad when looking straight ahead. But see the difference with a TrackIr and looking out to one of your sides, and 30 FPS looks like a slideshow compared to 60 FPS.

 

 

It's this typical attitude that's the reason many people are still humping along with 30-40 FPS on some of the latest/greatest hardware you can get for money. On a game engine that have had 10 years to optimize and tweak.

 

 

 

Mirrors/Reflection off the canopy.

 

Have mirrors off

[SkateZilla]

On a game engine that have had 10 years to optimize and tweak.

 

The Engine is 10 years old. When they originally coded it, GFX Cards were ALOT different.

 

Now 10 years later, the same engine has had effects and layers added to it to make it look better, while still running the same base code. You can only add so much to an aging engine before it starts to have qirks.

 

Run LoMAC and then Run DCSW 1.2.2 and tell me the terrain looks the same, it doesnt. They've added so many things to the same engine that afaik, prolly want coded to last this long.

 

And 10 years ago, everything was still single threaded and usign 32-bit addresses, GPUs with Separate Geometry Renderers and Shader blocks.

 

 

It's pretty much the same as running Windows 95 and adding everything from Win7 to Windows 95 Core. IT's gonna run slow as hell because it was coded to Run Single Threaded w/ less than 4GB of Ram.

 

 

 

 

 

 

Have mirrors off

 

There's still canopy reflections, and the shader is active whether or not you look at the engines.

[TZeer]

Sounds reasonable :)

 

But it does not explain why there is no such effect when the plane is controlled by the AI. Only when you fly it yourself. Doesn't matter if you go external view or internal.

 

And no such effect when flying the SU-25T.

[TZeer]

Tested on the A-10A. No performance drop with heat blur. So far only A-10C who has it.

[SkateZilla]

6DoF Pit or AFM or Combo of both, since they use more CPU power than SFM.

[TZeer]

What you saying SkateZilla?

 

That it is due to lack of cpu power?

 

The bug is there as long as you are controlling the aircraft. No matter if you are flying manually or on autopilot.

 

The bug is also there if you look at the aircraft in external view.

 

But, if you zoom out, the reduction in CPU usage and GPU usage goes away when the heat blur is no longer visible.

 

It has nothing to do with the amount of CPU power available.

[BRooDJeRo]

The 80's where easy. Just blame it on the gremlins and all problems would go away...

[TZeer]

Update, running single card GTX titan. No FPS drop visible.

 

Don't know if it got fixed in the last patch or it's a SLI issue.

[djwave]

tzeer, how much frames have you in takeoff trainning mission, inside the cockpit (default view)? with my titan, with all option in high cant get more than 26-28 frames, if i see directly to terminal installations my frames go down to 22. And another question, what gpu usage you have? my titan gpu usage dont go more than 70% all the time, in one or three monitors. ARRGHHH

[karambiatos]

Sounds more like nVidia needs to make a better SLI Profile for DCSW, as the work load isnt distributed properly. which causes drops in FPS and GPU usuage in your case.

nvidia needs to make SLi work better period, its really terribly done in almost any game and work load is probably only properly distributed in 1% of games.

 

i just tested the stuff with me, and there is no difference in the cockpit between having heatblur on or off, both in and out of the cockpit.

 

obviously i get more FPS outside of the cockpit but that is because theres no render to texture stuff

Edited May 5, 2013 by karambiatos

[TZeer]

nvidia needs to make SLi work better period, its really terribly done in almost any game and work load is probably only properly distributed in 1% of games.

 

i just tested the stuff with me, and there is no difference in the cockpit between having heatblur on or off, both in and out of the cockpit.

 

obviously i get more FPS outside of the cockpit but that is because theres no render to texture stuff

 

Not possible to turn off heat blur atm. It's a known bug.

[jbrking]

i upgraded my pc today ended up actually losing frames somehow in the process. all other applications however have gained performance.

 

was running this..

 

Windows 8 Pro 64-bit (6.2, Build 9200)

MS-7390

AMD Phenom 9750 Quad-Core Processor (4 CPUs), ~2.4GHz

8192MB RAM

AMD Radeon HD 6900 Series

 

almost no change, i never looked at my frames with the original setup but with the setup below with details switched to low I am lucky to get 30fps. It doesnt seem to have improved much at all performance wise.

does this seem right?

 

Windows 8 Pro 64-bit (6.2, Build 9200)

GA-990FXA-D3

AMD FX-8320 Eight-Core Processor (8 CPUs), ~3.5GHz

8192MB RAM

AMD Radeon HD 6900 Series

 

any ideas would be great..:music_whistling:

[TZeer]

Have a look in this thread :)

 

http://forums.eagle.ru/showthread.php?t=107551

[Kaaboom]

Hows about 2x R9 290?Anyone playing with these cards?