Understanding X-Plane performance

[marty2756 65]

Well, played cranking up world distance to very high, airport detail to max, antristropic to 16, cars, and objects.

All combinatios resulted in the same (17) or less FPS, altought not too much, all to max got about 13 or 14fps, something expected somehow.

 

Anyway, I could lower everything down,... till I get MORE than those 17 ugly fps.... but the the question still is,

why ... if I don't have a CPU constraint neither a GPU contraint I ONLY get those fps.

 

Quoting from Ben Dev Blog:

"Here’s the key point: your framerate is determined by the processor that is not idle.  If your GPU is idle and your CPU is not, you are “CPU bound”; if your CPU is idle and your GPU is not, you are GPU bound."

 

So in this situation... my GPU is Idle by far,,, and my CPU is idle too , altough not so much as GPU.....

so.... WHAT is "determining" my 17 fps limit ?

[mtaxp 666]

I didn't tell you to crank everything while i'm expecting that you'l get solid 30,wanted to see how cpu affected.

Is the cpu usage remains the same even after that?

[Blaze 102]

So in this situation... my GPU is Idle by far,,, and my CPU is idle too , altough not so much as GPU.....

 

so.... WHAT is "determining" my 17 fps limit ?

 

Do you happen to have any AI Aircraft, especially default ones loading into the sim? They tank my FPS even the ones that are suppose to be optimized. Also are you seeing these low fps everywhere or in a specific location, maybe a bad scenery? Lastly from what I have read on Ben's blog I would never consider running texture compression especially with 3-4gb of vram but I suppose that's a personal preference.

[Ianrivaldosmith 5,317]

 

 

Lastly from what I have read on Ben's blog I would never consider running texture compression especially with 3-4gb of vram.

 

Well with everything maxed out, there is no choice, otherwise it is too much. Way above 4GB. Trust me, I know, I have 4GB....and I've tried! 

[Blaze 102]

 

 

Well with everything maxed out, there is no choice, otherwise it is too much. Way above 4GB. Trust me, I know, I have 4GB....and I've tried!

I find it hard to believe you could even have playable framerates with everything "Maxed Out" so what's the point?

[Ianrivaldosmith 5,317]

I find it hard to believe you could even have playable framerates with everything "Maxed Out" so what's the point?

 

I can maintain 30FPS, not 'everything' is maxed, but I put my GPU to use, so things that are GPU bound I max, I have very high settings. Lowest I go is around 22 in somewhere like London. And I know if I don;t compress textures, I go way over. I am at 3800MB on GPU-Z in an OSM city area, with compressed. Imagine uncompressed?!

[Blaze 102]

 

 

I can maintain 30FPS, not 'everything' is maxed, but I put my GPU to use, so things that are GPU bound I max, I have very high settings. Lowest I go is around 22 in somewhere like London. And I know if I don;t compress textures, I go way over. I am at 3800MB on GPU-Z in an OSM city area, with compressed. Imagine uncompressed?!

Cool, glad it works for you.  Now back on topic...So the OP got a new card  went from a 580gtx to a 780ti and doesn't seem happy with the results? Hmmm, sometimes the simplest solutions often get overlooked; did you update your drivers? Any Nvidia or Nvidia Inspector setting that might be causing the poor performance?  Once those are checked why not go to a default location and "set all rendering options for maximum speed" then build yourself up increasing the rendering options as you go? Might help in troubleshooting the issue...Good luck

[marty2756 65]

@mtaxp:. cranking up those options,  gradually increases CPU usage reading within X-Plane, yes,.... goes UP till 0.945 ~.... (with everything at max), except Cars, that I have it at Kansas Residential.

I understand your point trying to maximize usage of CPU right ?

But do you get my point ? What I try to achive is..... STAY with my original rendering settings... and understand... WHY is that I can't get MORE fps (than 17),,, if there is ROOM left ,, (idle processors) for CPU as for GPU.

Don't know if I you get what I mean.

@Blaze: yes I have 6 AI aircraft, but those are Mortens AI,, very low on FPS... by the way.. I tried setting them to 0 AI.. and If I get 1 more FPS ... is too much.. anyway .. if this would be the cause... my point still remains... why ... if there is processing power left on both cpu and gpu sides... can't get more fps. "Bus" is the only thing that comes to my mind.

[saed45 38]

i know this might sound weird but is there any way you can partition you hd and install a fresh windows and xplane. something sounds very wrong with how much FPS your getting with ur HD

[mtaxp 666]

@marty2756

Maybe some conflicts with the older ones,which common when changing the GPU...Try to unistall anything that's realted to NVIDIA and then install a FRESH new driver.

Moreover,as @saed45 said try to install a fresh copy of your operating system,and then install new fresh drivers

 

Usually those situations are the result of CPU bound,I mean...you are CPU bound (GPU is almost idle,but CPU does some work though) but your CPU has much more room to work... 

[s0cks 116]

My suggestion would be to run nVidia inspector and see what your memory usage is. You might be surprised. In game mine said ~1300MB, but N.I showed I was maxing out my 2GB card completely (god damn it why didn't I get the 4GB version!?). Anyway, changed a few settings until it was at ~1800-1950MB and saw much smoother framerates with little visual impact. From memory, world draw distance and in-game AA had the most effect on VRAM.

[marty2756 65]

I will try to reinstall Windows, and test about VRAM real usage with nvidia inspetor. (Altough I don't think that x-plane saying 1.2 GB usage will exceed 3 GB of 780 TI.

Anyway... I would like to see similar tests , if anynone also finds low FPS having left both GPU and CPU power....and...

if someone can explain what is acting as the constraint there... as I said.. I just could imagine Bus... or.. well... x-plane multi-threaded design (limit imposed by threads coordinating work between cpu cores)... again ... I don't think this is the case.

[s0cks 116]

Well, X-Plane showed 1300MB and I was maxing 2GB, which means it wanted more than 2GB - so who knows. Maybe it could be demanding 3GB or more. I suspect XP doesn't count the extra VRAM usage imposed by AA.

[Slayer 190]

Your CPU is the limiting factor. Although helpful, that CPU meter doesn't always tell the full story. Bottom line is if your CPU is overburdened it can't send enough data to the GPU.

 

Just do it the old fashioned way and start from scratch with lower. Leave textures on very high or extreme, HDR should be on, set your view distance to medium or high, AF 16x. Roads cars etc on lowest setting as well as shadows and water. Then see what your FPS is before touching anything else. Then raise them one setting at a time. The thing to remember is always set your view distance, textures  AA and AF first before raising anything else. The reason is because those have more of a global impact on your autogen settings.  I spent weeks tying to get the best out of XPX on a surround setup (with this you can really see which settings hit the hardest as everything is magnified by 3x)

 

Oh yea another huge impact ...since I didn't see it mentioned, "cloud puffs"....this setting at default will kill most systems. try 10 or 20, not 60. Also you can go in and set weather to CAVOK

[marty2756 65]

Your CPU is the limiting factor. Although helpful, that CPU meter doesn't always tell the full story. Bottom line is if your CPU is overburdened it can't send enough data to the GPU.

 

Agreed... , altough I find hard to accept my CPU is exceeded in this situation (not only by X-Plane saying 0.808, but the most busy CPU Core  near 75%, I mean ... values really below the max). But well .. GPU is not for sure.... so.. CPU should be.

Will try lowering these settings , starting from there and see whats hitting so hard CPU.