Question to the developers CPU 16 cores

[Perfectflight]

Question to the developers
Prepar3d is very CPU heavy and my question is if a 16 cores e.g. 3950x brings benefits.

my 9900K specially orbx germany with fslabs a320 fall the fps at the landing approach to approx. 25 fps. - 33 fps blocked
shadow, HDR, is off, etc.

Prerpar3d skates quite well with the 9900K and it would be really interesting how 16 cores behave.

Intel will soon release a 10-core CPU, because you need a new mainboard and in the next generation again a new board. Thus, the AMD platform would be future-proof

On the internet you will find no information and the risk would be high and that costs a lot of money, just to try it to swap the system

Sorry for my bad english but i hope it is understandable

[MikeB54]

Keep in mind that this is a community forum. Directing a question directly to the developers may get answered, but most likely it will not.

That said, P3D is, for the most part, a single threaded program. Almost all of the processing is going to take place on one core. It is technically possible to configure the thread to run on a dedicated core of your choice but I haven't read anything on any of the threads on this board that indicates you will get a significant performance boost out of that. Where you will get a performance boost is from a CPU running at as high a clock speed as possible. I run on an i7 4790k. It's a 4 core processor and I run it with Hyperthreading off. Core 0 is always running at close to 100% where the other 3 cores run at close to idle. Stock clock speed fort the CPU is 4 GHz but I have it overclocked to 4.5 GHz and I have no complaints with performance.

Bottom line, you aren't going to get that much of a performance boost just because your CPU has more cores.

[Perfectflight]

Keep in mind that this is a community forum. Directing a question directly to the developers may get answered, but most likely it will not.

That said, P3D is, for the most part, a single threaded program. Almost all of the processing is going to take place on one core. It is technically possible to configure the thread to run on a dedicated core of your choice but I haven't read anything on any of the threads on this board that indicates you will get a significant performance boost out of that. Where you will get a performance boost is from a CPU running at as high a clock speed as possible. I run on an i7 4790k. It's a 4 core processor and I run it with Hyperthreading off. Core 0 is always running at close to 100% where the other 3 cores run at close to idle. Stock clock speed fort the CPU is 4 GHz but I have it overclocked to 4.5 GHz and I have no complaints with performance.

Bottom line, you aren't going to get that much of a performance boost just because your CPU has more cores.

hello, yes I had the cpu too and changed damlas to a 8800k.

This change has generated more fps.

8800k on a 9900k I have not more fps, but they are more stable

[JorgenSA]

Set the AffinityMask properly in Prepar3D.cfg and you'll be using the cores as best can be done with the present technology.

P3D is still very much FSX legacy, and as such primarily single-threaded. Therefore, raw CPU clock rate still matters more than the number of cores, in spite of so many people spending money on multi-cored CPUs.

P3D can probably not be re-programmed to be truly multi-threaded, so a multi-threaded flight simulator would most likely be a wholly new developed one, and probably not with a lot of backwards compatibility towards FSX like P3D. And that this would be developed more or less from scratch would mean it would be expensive.

Just a few thoughts....

Jorgen

[Perfectflight]

Set the AffinityMask properly in Prepar3D.cfg and you'll be using the cores as best can be done with the present technology.

P3D is still very much FSX legacy, and as such primarily single-threaded. Therefore, raw CPU clock rate still matters more than the number of cores, in spite of so many people spending money on multi-cored CPUs.

P3D can probably not be re-programmed to be truly multi-threaded, so a multi-threaded flight simulator would most likely be a wholly new developed one, and probably not with a lot of backwards compatibility towards FSX like P3D. And that this would be developed more or less from scratch would mean it would be expensive.

Just a few thoughts....

Jorgen

So affinity mask does not recommend fs labs and my cpu scales with all kernels split. That's why I do not need it. Because prepar3d scales so well, my idea is that 16 kernels are better. I made a video where you can see the utilization


https://www.youtube.com/watch?v=vI4Oo9L ... e=youtu.be

[Perfectflight]

now a video with all 16 threads

https://youtu.be/jv92YCgFmDM

[JorgenSA]

Here's what you need to do:

Apply these tuning items as required for your system:

https://www.prepar3d.com/SDKv4/prepar3d ... ation.html

Then calculate the AffinityMask settings properly:

http://www.gatwick-fsg.org.uk/affinitym ... m=utilties

Jorgen

[Perfectflight]

Hello thanks for the information

I have the core utilization no problem
my question is whether more than 16 kernels will be generated for stable fps.

[JorgenSA]

Take another look at the tuning guide - in particular, limit your frame rate to somewhere between 24 and 30 - which is all your eye can see anyway.

You will get a more stable, consistent frame rate, and a smoother, more life-like simulation.

16 or more cores will not get you anywhere, 2 to 4 cores running at a clock rate like 6 GHz will - if such a CPU existed.

You have to remember that P3D is still basically a single-threaded application (with big emphasis on the highlighted), able to use a couple of more cores for secondary tasks. This is inherent in the coding that dates back from the FSX days.

For those not familiar with the jargon, single-threaded here means able to use one core only.

Let's just tackle the GPUs as well here: P3D is better able to have the GPU offload the CPU than FSX was - but only to some extent. A nVidia Titan is not going to do anything for you without a powerful (over 4.5 GHz at least) CPU. We had one thread here recently where a user had a nVidia 2060 TI - with a 2.6 GHz CPU (if my ailing memory is correct - close enough, for sure). Sorry, that one is going to fly like a lead glider.

Jorgen

[JorgenSA]

I forgot to add something here: the reason that you have to have a powerful CPU feed a powerful graphics card is very simple - the graphics card needs to get data fed to it quickly so it can squirt out nice pictures for your enjoyment.

Without a powerful CPU, a powerful GPU would be sitting idle a lot of the time - kinda counter-productive.....

Jorgen

[CplDaniel]

Question to the developers
Prepar3d is very CPU heavy and my question is if a 16 cores e.g. 3950x brings benefits.

my 9900K specially orbx germany with fslabs a320 fall the fps at the landing approach to approx. 25 fps. - 33 fps blocked
shadow, HDR, is off, etc.

Prerpar3d skates quite well with the 9900K and it would be really interesting how 16 cores behave.
Intel will soon release a 10-core CPU, because you need a new mainboard and in the next generation again a new board. Thus, the AMD platform would be future-proof

If anyone has an inconsistent performance issue with the 9900k, my first hardware solution to troubleshoot would be motherboard power-delivery issues that often arise from pairing a budget Z390 that was intended to be entry-level and paired with an i5 9600 rather than a high-performance power-hungry 9900k OC; and second, RAM of course can sometimes be a finnik-e constraint in high-performance multi-core application.

That said, except for one application, I think AMD's 16 cores will cause more problems (with thermal throttling the top-core speed) than it solves through supporting parrallel operations running across 16 cores. The AMD cores don't hit as high as the Intel chips, and when they do hit the advertised boost-clocks, it's invariably for just a fraction of a second before throttling back down into the 3 to 4 GHz range.
BUT THE 12-16 CORE AMD CHIPS MIGHT BE GREAT for allowing operations that might have once been handled across two physical computers with an Intel i9 to now be handled on a single system, which certainly is value in and of itself.