Is MS2020 CPU limited .....

[renault]

 

I decided to create a new post for this subject as I had commented in another members topic and it would be unfair to them @B12

to continue the discussion in that area ....

 I had responded to another member @Dadtom65 who had asked the question "Is MS2020 CPU or GPU restricted"  and my answer was that in my experience it was gpu constrained.  PiotrMKG @PiotrMKG commented that in his experience he found the opposite.

 

I started thinking about it and this morning decided to investigate further.  I was incorrect in my previous comment and I now believe that Piotr's perspective is totally valid.

 

Almost all simulators have been coded to do most of their computational work on a single core and do not do well in sharing workload across multiple cores.  MS2020 in its current state , using DX11 is no exception to this.  If you wish to investigate further , a Google search will turn up a vast array of discussion on this subject.

 

I hope that the following will shed further insight on this.  

 

I ran two cases . The first is with no frame rate cap applied externally to the simulator. The second is with a frame rate cap of 30 fps applied through Nvidia Control Panel. This is my personal choice on how I wish to control my simulator.

 

There is no right or wrong way to run a simulator in my opinion.  It is purely a matter of personal preference  on how you wish to set up your system  that is workable for you.

 

 At the end of the day, all that matters is that we all enjoy what we are doing.

 

My system has a i7 9700K which is boosted to 4.9 ghz, 32 GB Ram # 3600mhz and a RTX 2060 super 8 GB gpu.  I have all my settings on Ultra and am using 2560x1440p resolution,

 

In my previous comment , I was focusing on average values of CPU utilization.  This is incorrect and one needs to look at individual cpu core behaviour.   This was where I erred and it does lead to an incorrect conclusion regarding CPU behaviour. 

 

This first screenshot shows the base condition  behaviour before MS2020 is started and while the simulator is loading.

 

 

 

The following screenshot show the behaviour at KSBA, Santa Barbara which is my chosen test airport.  There is no external limit on fps and this represents the limit of what my system is capable of under this test condition.  

 

 

It illustrates two aspects . Firstly ,  Core 7 is completely saturated at 100% utilization, while the other cores are not. It supports Piotr's comment completely, but also illustrates that in its present coding MS2020 could be improved  to more fully utilization all cores. Hopefully this will happen in further updates.

 

Secondly it illustrates that an average CPU utilization is completely misleading in this scenario.  The "devil is truly in the details"  as the controlling parameter is the single CPU that is maxed out at 100% utilization, not the GPU running at 95% utilization.

 

The second screenshot illustrates the behaviour  when a frame rate limit cap of 30 fps is imposed.  Again , Core 7 is still carrying the majority of the computational load,  although it is no longer at 100% utilization.  Again, average CPU utilization is not a good indicator of actual system behaviour.

 

 

I again emphasize that this is a personal choice on how I wish to use my simulator.  I am not advocating for or against it .... individual choice is what works best for you.

 

There are members who are far more expert in the nuisances of CPU saturation than I and if you wish to comment on this please do so. However it seems to me from my limited understanding that changing to a faster CPU or one with many more cores  will have limited benefit at this point in time , aside from cpu speed and improvement  which might help the single core doing the majority of the workload.  However, that depends of course on the starting condition of the base cpu frequency and if you have a fast cpu then the uplift may be minimal. 

 

What seems to be needed is the ability to make better use of all the available cores and better equalization of cpu utilization by redistributing the workload more evenly and moving the major load off the single core which gets completely overloaded.  Hopefully this will be addressed in future updates and moving to DX12.

 

I hope this is of interest to other members

Cheers

Pete

 

 

 

 

 

[B12]

You've done your homework there Pete, well done mate.

Great post, its not just that easy for many of us and why we choose the hardware we do I guess? Or at least for me I suppose? I did choose my recent PC hardware upgrade with FS2020 in mind, but also DCS that is going to go through big changes soon that can use more cores and GPU grunt.

Different Sims have different results, they also evolve fast too. Military and Civil Aviation ones and we all use our CPU and GPU's for more than just flight simulation, pretty sure about that my friend.

My advice for anyone upgrading hardware now or in near future, study Pete's results they are very valid for the parts he benchmarks, but look at a lot more others results too benchmark wise for what you want, because we are all different and have different needs for a PC computer usage

There is no perfect PC spec for Flight Simulation.

I went this time for the AMD 5950X CPU, an RTX 3090 24 GB GPU ... it was a struggle to buy them both from new but was determined, it was a difficult choice going from Intel good CPU's to AMD this time too, big dilemma, but felt the time was right.

At end of day ... I've never really bothered with benchmarks, ever ... the best benchmark I know is our own eyeballs and our brains in simulations we use in this hobby, if its fluid in flight with as high settings you can manage, then that to me is the ultimate goal.

Benchmarking PC hardware properly is a good skill, but for me ... I prefer to just go Flying, spent a good hour flying just now before coming back to this post and it was so soothing, relaxing ... for me, that's all I want ... have my new parts, in the next 3 years before I set my target for a new build, something new will be along hardware wise, DDR5 ram on horizon already ETC.

Its good to benchmark, but please don't forget to spend time enjoying what you benchmark for.