Hi Folks,
I’m assisting my father who has recently purchased a high end machine specifically to run flight simulator. The spec of the system is as follows: Alpine Flight Computer Systems EGLL System
It was purchased as specific system designed to run flight simulator. The company he purchased it from is working through various options / tweaks with him but was keen to see what advice the community may have and if there are some generic guides one can follow.
The resolution used is 3440×1440 and most of the settings graphics wise are out of the box. There are no add-ins installed and in fact no other software on this machine presently.
In flight everything seems to be fine. He had experienced various crashes previously and the company he purchased the machine from sent some new memory which so far seems to have addressed the issue. The problem is that when taxiing or taking off, at slower speeds there is some noticeable juddering with the graphics.
F.Sim is a game.A software.
You never “build” a pc just for a spesific software.These are excuses that companies say to people that are not so familiar with pc specs and collecting-modifying hardware.
You just build a good machine and it can play anything.If something is not quite as it should,then it is not the machines fault but the softwares.
Congrats on the build, those are really good specs on that machine! 
From my personal experience I came to the conclusion that in-flight stutters are correlated with “Terrain LOD” setting (in my case the sim is CPU limited). My ideal setting is now 150 for jets and 250 for GA aircraft.
However I still noticed significant dips in FPS during the takeoff/landing rolls (down to around 20FPS) and my guess is that this is a bug within the sim itself because the stutters disappear a few seconds after liftoff, and everything seems normal during the climb/cruise/descent stages.
So the tl;dr conclusion (at least in my case) is: if stutters only occur during takeoff/landing rolls then there’s not much to do about it except waiting for a fix.
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Doing exactly what is said in video below really helped smoothed my experience, especially around airports.
Other than that you also have to optimise in game GPU usage v CPU usage so you are not CPU limited. ie make your graphics card work more. At 1440 a 3080 may not be being working hard enough. There are a lot of threads on here about that. You can push the graphics card harder by turning some graphical setting to ultra, running at higher res, or higher render scale in FS graphics options etc.
Also make sure your windows desktop res is same as in game res as scalings can also slow things down a bit.
Also stutters can be a result of CPU being too busy, so turn LODs down a wee bit like 200 for TLOD and see if things improve.
Also there is a Window graphics setting called Hardware Accelerated GPU Scheduling which most people find they have a better time when switched off.
Other than that try doing what this video says. 
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Also a few specific tips right from the recently updated MSFS zendesk if they help:
All versions - How to improve the performance – Microsoft Flight Simulator Support (zendesk.com)
If it’s a Win 11 machine, ensure VBS memory integrity is disabled. And if you’re running DX11, you can set low latency mode to on or ultra in the Nvidia CP.
With that GPU and resolution, you can run on the ultra graphics preset, but notch back render scaler to 85%-90%. Also try and keep the terrain LOD where it is if you’re trying to avoid stutters.
The other piece of equation is the display - are you running a g-sync or freesync monitor?
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Good suggestions in the Pilot Pete video.
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So the monitor is a Samsung CJ791 and that shows as a FreeSync display. It’s running W10 21H2. HAGS is disabled and it was by default.
I tried the suggestions in the video and it made a vast improvement. I might turn down scaling some more as juddering still present. The biggest help seemed to be enabling Intel Adaptive Boost Technology but then I had some lockups / reboots.
Have you tried switching FS to dev mode and looking at whether you are CPU (mainthread) limited or not. Another person on here had a high end GPU and recently optimised/improved using this (30FPS locked) method, but also I think dropped some LOD’s down a bit due to CPU mainthread being limited.
Apologies if you have done this already, but a few screen grabs say with your aircraft on the ground static at Heathrow say would help see whats’ going on with Dev Mode and FPS counter enabled. Capture it at full screen so we can see the proper FPS rather than windowed mode. The key with these systems is to balance the CPU/GPU load. CPU load primariily reduced by reducing Terrain LOD & Object LOD sliders down abit from max say 150 instead of 400 for TLOD and 100 instead of 200 for OLOD then see whether the mainthread is limited in the FPS counter before/after.
Render scale is used to keep GPU busier/less busier (if required) so a render scale of 125% will keep GPU busier, but for not exta visual gain where as a render sale of 80 will keep PU less busy (if you are GPU limited).
Other things to check. Is your windows desktop running at same res as FS is? There are always resources used up in pointless rescaling. So for example if your windows desktop is runing at 4K (2D) and you are running FS at 1080, there will be a resource hogging rescale happening. Much better to switch the windows desktop and FS to run at same resolution. Note this isn’t the same as the in game render scale setting I previously mentioned.
Juddering /stuttering is usually a sign of being CPU (mainthread limited) so those screen grabs of dev mode FPS would be useful to see.
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Thank you. Next time I am round and at my Dad’s machine, I’ll try in Dev mode and capture the FPS. With an i9 11900K and a 3080, I would be surprised if I was limited much by either resource.
I dropped Render scaling from 140 to 100 based on advice elsewhere.
The res is 3440×1440 same as native.
Similar system and I run render scale at 150 to force a GPU limitation rather than CPU.
There is a whole thread on this I’ll try find it for you.
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and I’d be surprised I you weren’t. FS is a program that needs to have CPU and GPU loads balanced to work well. It’s very common to be mainthread limited (on one of the CPU cores). The solution is nearly always to reduce CPU load via reducing LODs a bit and upping GPU load. One of the ways to up GPU load is via increasing render scale to bigger than required so say 125%. The 1440p res you are running at is probably quite low for a 3080. It would quite happily run at 4K if your monitor supports 4K. If not then increased render scale at 1440 may be necessary. You can of course also keep the GPU busier with most of the other graphics sliders at high/ultra settings. You do need to check that you are not CPU mainthread limited though, so use the dev mode FPS counter for this purpose. Just about every question on this forum re high end systems and poor performance/stutters relates to this issue.
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Ps. By dropping render scale you made your GPU less busy, thus making the CPU busier with respect to the GPU which will be sitting at low usage/idle waiting on more data from the CPU mainthread which will be the limit. You have to load up the GPU. Either run at 4K (if you have the monitor), if not then render at higher value 125% or 150% and put most graphics sliders to high/ultra. If that isn’t smoother and you find you are still cpu mainthread limited then reduce the LODs which use CPU resources. The system will balance and the system will be blazing fast and smooth.
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Thanks, so although it may seem counter intuitive, upping the render scale to say 140 from 100 in our case may actually increase performance by pushing the GPU harder? I presume this isn’t in isolation and I must lower to LODs a bit also.
The resolution I am running 1440 is limited by the monitor.
Is the consensus that it isn’t uncommon for an i9 11900K to need to throttle back on the LOD’s? I see what you mean by main thread limited. It seems the sim isn’t optimized in this regard.
I’ll have a play with dev mode.
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I have an AMD Ryzen9 5950 and I was CPU mainthread limited so yes it can be the CPU. FS only uses one core (mainthread) effectively so it quickly gets limited and causes these issues. The GPU needs data otherwise it sits there with nothing to do and can manifest in stutters. Load up the GPU more to keep it busier and back off loading the CPU more (reducing LODs a bit) and the system will perform as you are expecting it to.
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The 3080 is almost too much GPU for you 1440 monitor. So at that res keep the GPU busier by upping render scale. A 4K monitor would be an option keeping the 3080 busier at a closer to 100% render scale. So yes 1440p may need 150% render scale to keep GPU busy enough at 1440p.
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I sometimes push 4k resolution on my 1440p to take the load off the CPU.
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I really hope with DX12 they figure out how to utilise the other cores effectively!
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I’ll believe it when I see it though. So many users expectations with DX12.
The thing I can’t comprehend is why MS don’t have an optimiser app for FS. Even if there was a 3rd party produced one, a small fortune could be made. It’s always the same issues cropping up, and FS is a resource hog of a program like no other. I mean who ever has to think of this load balancing with any other piece of software. It is unique in this regard as far as I can tell.
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Yeah I never seen anything like it before! It’s beyond frustrating…
No way should someone be struggling with the latest tech!
It’s borderline useless at times because certain areas are unflyable.
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