Hmm, interesting Ed.  I've already stated it is entirely possible there is 'something amiss in my P3D install...' as part of the differential diagnosis.  The reason I made this post in the first place was to try to find out if this is standard behavior in others' experience using similar hardware.  It was helpful to get this sort of reply affirming my very own experience to a tee:              #5            

 

Whereas others here don't comment on their experience, but instead pose non sequitur responses about whether or not I should expect more, or that 'you aren't happy w/ 25fps....'  

 

Ed, what is your experience in this scenario?   High CPU demand, marginal frame rate, and low GPU utilization? 

Nope.

 

I get the performance I expect... as long as I don't do something dumb... like load up ASN with cloud shadows and 5 layers of clouds... etc.

 

Look, you're running a better system than I am... but I know with default aircraft and stuff... I see NO ISSUES.

Noel, do you have SGSS enabled in NI? I found it to have a huge impact on fps in urban areas when flying Orbx PNW.

Noel, do you have SGSS enabled in NI? I found it to have a huge impact on fps in urban areas when flying Orbx PNW.

No, not in this situation.  But my understanding is that task is more in the domain of the GPU, and recall GPU usage in this scenario is only 45-55% of full, which is largely the issue I see.   The behavior I see points to CPU-boundedness.  The additional support for this interpretation is the fact that autogen & vegetation sliders don't have a huge impact on this, CPU overclocking improves it in typical fashion when the situation is leaning towards CPU-boundedness.  It's always looked this way to me, in the complex scenery areas, and this seems to have gotten worse since 2.2 arrived, though I'm not certain on the timing as that was about the same time I installed NCA.  

No, not in this situation.  But my understanding is that task is more in the domain of the GPU, and recall GPU usage in this scenario is only 45-55% of full, which is largely the issue I see.   The behavior I see points to CPU-boundedness.  The additional support for this interpretation is the fact that autogen & vegetation sliders don't have a huge impact on this, CPU overclocking improves it in typical fashion when the situation is leaning towards CPU-boundedness.  It's always looked this way to me, in the complex scenery areas, and this seems to have gotten worse since 2.2 arrived, though I'm not certain on the timing as that was about the same time I installed NCA.  

 

Well, it's not always that simple. There is also bandwidth limitations and rendering information that must be done on the CPU before it can be sent to the GPU.

 

The reason I asked is that I was only seeing 45% GPU usage, and other than turning autogen completely off, I couldn't get above 15fps @ KPDX. Like you I didn't think it was a GPU related issue due to the low usage but alas it turned out that SGSS was the problem. Obviously not the case for you. Worth asking though!

Nope.

 

I get the performance I expect... as long as I don't do something dumb... like load up ASN with cloud shadows and 5 layers of clouds... etc.

 

Look, you're running a better system than I am... but I know with default aircraft and stuff... I see NO ISSUES.

 

Ed, I believe you, you see no issues.  Good luck to you...

Well, it's not always that simple. There is also bandwidth limitations and rendering information that must be done on the CPU before it can be sent to the GPU.

 

The reason I asked is that I was only seeing 45% GPU usage, and other than turning autogen completely off, I couldn't get above 15fps KPDX. Turned out that SGSS was the problem. Obviously not the case for you. Worth asking though!

Sure.  I can say all of the features that in my mind align w/ more GPU oriented overhead predictably scale up and down w/ the associated sliders, and even autogen applies to some degree.   The more pure GPU effects which I assume to be tessellation, HDR, cloud and object shadowing, all of these increase GPU utilization up to 99%.  But the real issue for me is low GPU, and full on overclocked CPU, and relatively low frame rates.  With or without clouds.  There's something in how fairly simple appearing rendering tasks take the CPU down at some level in this situation, for example 30 feet away and pointing at Gate 1 at KSFO.  About all that's in your view is a wall.   In fact, you can do the outside view only (turning off the VC) and the frame rate stays the same, around 22.  So ultimately this doesn't bode well for complex PMDG planes in this scenario unless there is coding optimization for add ons in V2.2.   Seems the obvious path to exploit is the GPU with more work in this scenario.   Apparently FB's KIAD will be using some texture formats that are consistent w/ 2.2 or something along those lines.   It may be the first peak into what optimizing code used for add ons may offer going forward.

Yeah, I agree. I find urban areas seem too demanding for what they are. I mean, GPU's are used to rendering graphics that blow anything you see in P3D out of the water. Surely it isn't too much to ask for it to render a few hundred, maybe even a few thousand basic blocks (otherwise what we call autogen buildings).

 

However the problem here lies in the fact that the GPU is waiting for instruction from an overloaded CPU. From memory (I may be wrong) the main core handles pretty much everything including flight dynamics, autogen, rendering instructions, etc... with the other cores simply loading in scenery data.

 

I also think you are absolutely right in that SLI is not going to help in these situations. It will only help when the GPU is the bottleneck, which at this time seems to be only when introducing cloud shadows, volumetric fog, etc...

 

There is still definitely work to be done. Hopefully it is achievable, but it is obvious that flight simulators are very demanding on the CPU. Most of the new additions (shadows, HDR, volumetric fog) are all very much GPU heavy, so at the core performance hasn't suffered too much. However, I still find it a little depressing that core performance hasn't changed significantly since FSX - with all the new bells and whistles disabled there isn't a huge gap. Again, hopefully things will improve.

I mean, GPU's are used to rendering graphics that blow anything you see in P3D out of the water.

They render a really, really limited scope and absolutely everything about the 'scene' is predesigned and 'baked'. No lighting changes as the day goes by, no weather changes as time goes by... no moving shadows. None of that stuff.

Ed, I believe you, you see no issues.  Good luck to you...

Sure.  I can say all of the features that in my mind align w/ more GPU oriented overhead predictably scale up and down w/ the associated sliders, and even autogen applies to some degree.   The more pure GPU effects which I assume to be tessellation, HDR, cloud and object shadowing, all of these increase GPU utilization up to 99%.  But the real issue for me is low GPU, and full on overclocked CPU, and relatively low frame rates.  With or without clouds.  There's something in how fairly simple appearing rendering tasks take the CPU down at some level in this situation, for example 30 feet away and pointing at Gate 1 at KSFO.  About all that's in your view is a wall.   In fact, you can do the outside view only (turning off the VC) and the frame rate stays the same, around 22.  So ultimately this doesn't bode well for complex PMDG planes in this scenario unless there is coding optimization for add ons in V2.2.   Seems the obvious path to exploit is the GPU with more work in this scenario.   Apparently FB's KIAD will be using some texture formats that are consistent w/ 2.2 or something along those lines.   It may be the first peak into what optimizing code used for add ons may offer going forward.

+1

 

My CPU Core one is hitting 100% and GPU LOAD at 40-45% at KSFO Gate 1 26FPS in the Carenado Bonanza no ASN.

 

Michael

SLi will help with SGSS AA ... which I would love to be able to use again and retain a fluid experience.

 

But I'm pretty sure that FB's KSFO (which was done a few years ago) is using techniques that P3D can't batch and hence increases draw calls making it less GPU dependent and more CPU dependent.  Also, is your testing done exclusive on the MD80?

 

For example, I can load up the LM/Carenados' A36 at the same location (KCCR) and I will get 40-45 fps, load up the Alabeo SuperSport and I get 27-30 fps ... both are what I consider "simple" GA aircraft so what's causing the drastic reduction in frame rates when using a 3D party Aircraft which has installer for P3DV2?  Or, if I load up the Aerosoft Twin Otter it'll drop but only to around 37 fps.  And finally if I load up the Carenado Phenom I get 12 fps with all 3 displays turned on (lucky for me I can turn two off).  

 

So what's happening here?  Visually all 4 aircraft look great but there is a DRASTIC difference in fps performance between them.  Maybe the MFD/PFD issues in the Phonem is a hint of what the problem might be?

 

Obviously there is something in these aircraft that is causing some type of shift from GPU bound to CPU bound ... what specifically I have no idea.

 

Cheers, Rob.

You're missing the point which is that there is 50% of the GPU sitting idle in this scenario.

But how you do know that your hardware and software combination can't run more than 50% of the GPU?

They render a really, really limited scope and absolutely everything about the 'scene' is predesigned and 'baked'. No lighting changes as the day goes by, no weather changes as time goes by... no moving shadows. None of that stuff.

 

You haven't played some of the latest games then! It's almost all processed on the fly these days, as well as adding post processing effects. Lighting especially! Have a look at the Frostbite engine (Battlefield, Need for Speed, Mirrors Edge, etc...), and the GlassBox engine (SimCity).

 

 

I find urban areas seem too demanding for what they are.

 

I had a similar situation at KSAC with FTX NCA - everything else default.  I was very surprised to find that auto traffic had a major impact.  At 30% traffic 20 FPS, 100% traffic 13 FPS,  0% traffic 30 FPS.  I am wondering if the extra roads and traffic in urban FTX NCA takes a big CPU hit,

 

You may want to play with this setting in this case (FTX NCA).  Just a suggestion worth trying.

 

Ken

I had a similar situation at KSAC with FTX NCA - everything else default.  I was very surprised to find that auto traffic had a major impact.  At 30% traffic 20 FPS, 100% traffic 13 FPS,  0% traffic 30 FPS.  I am wondering if the extra roads and traffic in urban FTX NCA takes a big CPU hit,

 

You may want to play with this setting in this case (FTX NCA).  Just a suggestion worth trying.

 

Ken

 

Yes, thanks I noticed a big impact with traffic too so set it to 0% for now (in Orbx areas). I just find it amusing that 3-4yrs on (since I was last simming) and a new computer and still performance is not far off what I used to get. Mainly because CPU's have not really increased in clock speed.

 

 

I just find it amusing that 3-4yrs on (since I was last simming) and a new computer and still performance is not far off what I used to get.

 

True.  I also think we push simming to our individual performance (e.g. FPS) limit.  So performance seems to stay constant.