My FPS/Stuttering issues are definitely caused by huge memory overuse. Yours might be too?

The above plot shows clearly that MSFS is taking far too much memory (system and GPU) and leaving nothing in reserve - bringing the system to its knees. 32GB of system RAM (plus a generous swap file allocation) and 10GB of GPU RAM should NOT get sucked up like that.

Something is very wrong with the games memory management.

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Agree 100% sometimes getting 30Gb usage from 32 available

That’s why I have 64GB and memory use random heads nor tail.

Using your RAM as much as possible isn’t really an issue if it is able to release it when needed. I’d rather see it as a good sign.
And just to throw my numbers in: I’ve got 16GB of RAM and it runs fine except for the short fps drops every now and then.

Not saying you’re wrong, but correlation isn’t always causation and it’s hard to tell the difference as long as you don’t have access to Debugging/Code or have hard crashes due to OutOfMemory errors (which I had in September last year).

Google Chrome is eating your RAM as well, but it’s not a bug but a feature since keeping data in ram for possible later use is exactly what the bigger amounts of RAM is for.
The more you have, the less it will have to drop from the cache and reload later when it’s needed again.

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Can’t concur with that. I have the issues even though at the time it shows only 20-30GB memory use (of the 64 I have). The only explanation could be that MSFS is not able to use the full amount of memory available, which would be pretty stupid …

But on the other had, that gave me an idea: since my physical memory seems to be more than adequate, I’ll try switching OFF the swap file completely. Maybe MSFS tries to put stuff in the swap file, even though it doesn’t have to. Worth a try…

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All I know is that after the UK update, MSFS was running great. After the update, it aint. I take off from my home airport .. 40 fps. After a couple minutes, 20 fps with stuttering no matter the nvidia driver rollback or any other of the normal suggestions.

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Have you checked how much of your GPU RAM is being used?

No, just had the FPS counter in MSFS and the Task Manager. I don’t think I can see GPU memory usage there, only GPU usage, right?
Can you recommend a tool to check that?

As a software developer, I am aware of the benefits of using RAM effectively. In an ideal world, the system would be using 100% of the RAM whenever required - the reason this doesn’t happen, is due to RAM being a shared resource which needs to be instantly available to the many processes and applications that make the Windows ecosphere.

If MSFS was running in isolation or had it’s own memory allocation, then absolutely - use it all.

But if another process needs it and there is none available, that process will (at best) stall or even fail completely. The OS (any OS) will start to misbehave as its core processes stall and once it starts rationing resources, EVERYTHING slows down. It may even take back memory currently in use by MSFS, causing caching issues.

Open Hardware Monitor is excellent for monitoring all system resources: https://openhardwaremonitor.org/

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Thanks. Will have a look later.

I have to say, I can’t replicate this behaviour. I have 64GB of RAM and on Ultra across the board, I’m only seeing about 12GB of RAM usage and ~10GB of VRAM usage. My issue is the exact opposite, under-utilised hardware.

it depends on where you fly.
If you mostly fly around AI generated parts of the world, around 12-14GB seems to be the norm.
If you’re flying around photogrammetry areas and/or large custom airports you’ll see it quickly rise.
This is where it’s nice to have more than 16GB of RAM, since you wont’ have to deal with cache swapping.

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So you’re saying that certain locations will use a lot of memory and have stuttering issues for some people? Like the reports are saying?..

I’ve found MSFS to roughly use 32GB of memory - when adding RAM and pagefile usage.
Not sure if that’s depending on RAM or is a general rule, but that’s the case for me.

Right now I have the FPS issue as well standing somewhere in the UK with no photogrammetry anywhere.
My RAM is used to only ~7GB of the 16GB and the pagefile usage is at 22GB. Still stuttering while I usually have 50-60fps at that location.
GPU memory is also used only less than half of the available (3GB out of 8GB).

So I don’t see a memory issue here, at least not for me, while I still have the fps bug that doesn’t recover. I already set daylight, set to clear skies, disabled online functionality, nothing affects the issue.

Going to main menu and respawning with everything set up the same:
RAM and GPU mem usage even went up, but fps are fine. So basically contradicting your argument about the memory usage issue.

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Thanks again for the link.

So I just had a try with different aircraft. And for once - bummer - I couldn’t replicate the FPS issue. I had it in autogen areas many times before, also with different planes (Arrow, Mooney, C152, FSX Tiger Moth)

Today I first tried the H135 around an area with photogrammetry. This was far from optimal. Looks like the H135 is pretty GPU memory hungry for some reason. My FPS went to 15 (photogrammetry) to 25 (autogen). GPU memory (8GB) was full. So no surprise there.

Then I switched to the Tiger Moth. It’s a very primitive plane in every aspect and the FPS shot immediately up into the high 50s to low 60s and stayed there no matter whether photogrammetry or autogen

Last not least I used the JustFlight Arrow. This held stable in the low 40s in photogrammetry and went up into the high 40s without. However I had to switch off the EFB (tablet) since this one actually kills off between 8 and 10 fps!

In all cases the GPU (3070) and CPU (R9 5950) loads weren’t anything really bad. 50-60% tops.

Both with the Arrow and the Tiger Moth, the GPU memory was only half to 2/3 used.

So unfortunately this did little to get closer to the problem except confirm that the type of plane used plays an important role.

Can’t confirm ram overuse. I have heavy stutters over the infected locations but still over 12GB ram free (of 32GB) and 1 or 2 GB left at the graphics card (from 11GB). It goes never over 24GB (so far :pray:). But nobody knows whats happens next.

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Just did another flight which turned itself into a test …
I used another very primitive FSX plane which ordinarily renders FPS in the mind to high 50s.

After flying a while suddenly the stutters came. Luckily I had the FPS still on and Open Hardware Monitor was still in the tray. Here are some screenshots:

Stuttering started suddenly.

was suddenly gone again

came back and stayed.

As you can see the scenery is all autogen for miles around. This is my home turf. Before SU2 I could fly with any aircraft at 40-65 FPS.

What’s also easily visible are the stutters themselves. During the time everything went back to normal all values in the FPS counter were smooth. Next thing you know everything went from a movie to a slide show. So it’s clear that it’s not just the GPU that simply can’t work fast enough to produce higher FPS. The performance jumps higher and lower within milliseconds.

CPU and RAM usage is very low. GPU is in the low 50s. So absolutely no strain here.
What’s also interesting is the fact that the value for GPU memory usage varies between the MSFS FPS counter (which shows 3668 out of 7275 MB if I interpret that correctly) and Open Hardware Monitor (which 7327 of 8192) and the Task Manager (7.2GB of 8 GB).

What’s even more interesting are those massive spikes in the internet connection. There’s nothing running on my computer that uses the internet apart from MSFS, and I’m flying at about half the speed I would drive in a car (35mph) in autogen scenery, so I see no need to download those massive amounts of data up to my max of 200Mbit/s.

Curiouser and curiouser as Alice would say …

I’m having what must be a ram issue. And it happens SOMETIMES when I fly over a heavy PG area. GPU ram jumps to nearly the full 8gb and uses additional shared ram, and normal physical ram exceeds 80% of my 32gb and it eats into the page file. Everything else stays low: CPU %, GPU %, network usage… The PG loads fully and quickly (no melted buildings etc)… The SIM looks amazing! It’s just an amazing slideshow.

What’s odd is that London has always been fine, Miami is fine since the last patch, Boston was awful during daylight but super smooth at sunset, and leaving this morning, and Detroit was near unflyable today, but has been fine in the past.

Would using background software to periodically flush standby ram or something help?

It’s so frustrating because I know my PC can run MSFS in ultra very well - until I get ram spiralling out of control, only some of the time.

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