I built a PC with what I assume gotta be decent specs to play MSFS20 and 24 on 1440p. Ryzen 7 9800X3D, Radeon RX9070XT, 64 GB 6000MHz CL30 and MSFS installed in an NVMe.
MSFS2024 works pretty well (except for the night lighting bug), the card is put to use (hovering the 100% GPU usage) and apart from some frame stability polishing that I have to figure out I’m in a big airport with a traffic injector on ultra settings and its usable.
Now for MSFS2020 I noticed my GPU draws no more than 80W. It always felt very janky but now that I noticed thats it’s not a good sign, no game does that. I open devmode and I get hit with Limited by Mainthread. Usual configs one can miss are okay, other games run great: Resizable BAR is enabled and default EXPO too. V-Sync is off, AMD chill and antilag off. I use the Hyper-RX profile to get the frame gen but its clear the GPU can’t to anything to help right now.
What could be the culprit? I don’t even know where to start from. I tried both DX11 and DX12, seems to make no difference.
You will always be limited by either GPU or CPU (Mainthread) - there is literally no way to avoid this. And considering how much more CPU-intensive MSFS is compared to GPU, most users are Mainthread limited more than they’re GPU limited.
Also you mention Resizeable BAR enabled - generally it’s been recommended by most to have this disabled especially if you’re remotely close to running out of VRAM (ie, not using a 24gb or 32gb GPU).
To actually troubleshoot your issue it would be more useful to see the entire FPS display and also understand a bit more about how you’re running the sim - what settings, what major addons, what scenarios are you using for testing, etc.
EDIT: I just re-read a little more closely to see that you’re only experiencing the Mainthread Limit + bad performance in MSFS (2020) - this would be because MSFS 2024 (after Sim Update 4) had MAJOR improvements to multithreading and puts your 9800X3D to much better use than MSFS (2020) ever has, and likely ever will.
I’m always limited by mainthread and performance is very good. As mentioned above you’re always going to be limited by something. Don’t worry about it.
EDIT: Sorry just noticed this was a 2020 thread. I don’t use that anymore but the same applies.
Mine’s Nvidia however in AMD’s control panel equivilent start by putting your specific to MSFS 2020 gpu profile back to default … and then work from there.
Hi! First of all thanks for your detailed response and willingness to help. Been busy with work so didn’t reply before. Resizeable BAR has been disabled and I think I observed a VRAM usage improvement, but I’m not sure yet. It will stay off.
So I fiddled around with settings and realized that I oversold MSFS2024’s performance because I was using the in-game options FSR3 toggle. I turned it off and immediately saw a slight yet noticeable graphic quality improvement. It is true that one can argue that I paid for the whole GPU and I may use the whole GPU including its AI-gen features but I honestly was always a bare metal rendering person because I like graphic fidelity. Also, I think the whole thing feels less jerky now when the GPU can breathe (VRAM), frame gen was good but unpredictable.
This now means I may be asking too much of the RX9070XT because this hobby needs expensive hardware for the best results, however I spent near 2000€ and I think I could work out a decent experience with what is still a 700€ GPU, but I digress, the bottom line is that I will test and target the best bare metal render performance, with all frame-gen, upscaling and the like features disabled in both sims.
MSFS2024 obviously dropped, however the clear difference remains: MSFS2020 is Limited by Mainthread with the GPU just sitting not fully used at 60% and no more than 150W and MSFS2024 always uses the 100% of the GPU, with its 300 W and so on.
Now for the testing scenario which I tried to keep the same: FBW A32NX latest dev branch with the same livery, LTFM from Flightsim.to, GSX enabled and FTSL traffic injection, with the sim’s parked and traffic aircraft disabled, DX12. Ultra preset to stress test the whole thing. These are the results:
Download and install CapFrameX. It has really helped me do comparative testing of all the variables that affect sim performance. Dev Mode is fine for a “snapshot” look, but CFX runs for whatever time period you choose (I do 5-minute runs) and you end up with a lot of useful graphical data. Here’s an example:
