*Still* Getting Constant Long Freezes During Flight


Ever since I installed FS on day one, I have experienced freezes in the menus but particularly in flight. These can last for up to a minute but always resolve. It makes no difference if I am in a high density scenery area or flying over fields. They seem to happen at random.

My system is an i9-9900K with 1 TB SSD (50GB rolling cache) and RTX3080.

I’ve tried everything I can think of. Does anybody have any ideas? Please? The sim runs fantastically at high settings but these freezes totally break immersion.

I’ve been having bizarre pauses and sluggish moments since the UK update. A lot of people have been talking about it, but nobody seems to know what the glitch is. Lowering settings should help but it doesn’t seem to work in this case. For your system, I’d imagine it would be stutter-free no matter what, so at least I know it’s not my PC lol.

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Have you tried without rolling cache? Myself and many others reported noticably better performance even though it’s counterintuitive. Make sure your Windows 10 is up to date.

This may sound silly but I had many complaints myself about performance, stuttering, minor freezing, and CTD, however after plugging the HDMI into my 60HZ@1440p input much of that has gone away. I didn’t realize until recently the HDMI inputs were different on my TV.

Rolling Cache makes no difference. Only way to stop the dramatic FPS drop is to turn the whole ONLINE FUNCTIONALITY: OFF

I remember Asobo / Microsoft did a server boot last week, could this be the reason…

Have you seen the console during this freezes? What does it say? And the FPS counter from the SDK?

I haven’t - I’ve just seen the numbers from MSI afterburner and the FPS is stuck at whatever it was before the freeze. I will try the console and the FPS counter and post the results back here.

Sorry to sound stupid but I’m not sure what you mean by console and what info you get from it. I have the SDK and know how to get to the fps counter in developer mode - it usually says maintread limited when I’m flying (not unexpectedly), I’ll check when it’s frozen

On one of the upper options (I think is Windows), you can select console. And there appears some messages of what the sim is doing at that moment. I found some issues while it converts some bitmaps. So maybe you can see if the sim is taking time to do something at the freeze moment.

Thanks I’ll give it a try

Didn’t see anything useful on console. Below is a screenshot of the sim during a freeze. I am using the showcase camera to quickly move around Heathrow, but I get freezes when flying, and also on the menu screens. This freeze lasted about 30 seconds

Some quick way to eliminate certain factors, you’ll need to do these either one-by-one or disable all of them and turn them back on in sequence, flying test flights in between.

Turn OFF any Live factors like:


Use preset weather, offline Traffic and ATC.

In addition, turn down their sliders if available like Traffic. Turn it to 10 from whatever it is.

What you’re trying to do is eliminate any streaming services that might impact sim performance.

I would also tell you to shut down Bing Maps and Photogrammetry, but I wouldn’t go there unless none of the above make a difference.

The stutters means one part of the sim is not keeping up. Is it scenery, weather, traffic, other? Process of elimination is the only way to go from here. Otherwise you’re just taking guesses.

None of these individual turn off won’t help. You need to turn whole ONLINE FUNCTIONALITY: OFF until an official fix for this comes.


This has become rather circular as the link you posted has a link to ‘Large Freezes During Flight’ that links back to this thread!

Today I am going to test: with all online functionality turned off, with weather, traffic and ATC turned off, hotspotting from a mobile that will give me 30MBps rather than 18 on my broadband and finally just reducing settings globally.

My hunch is that this has to be something linked to streaming as every other game I run (I know fs is a sim not a game for any pedants out there :slight_smile: ) has not problem at all on my system.

I may even have a fun couple of days and reinstall everything from scratch!

A possible cause of program freezing is Windows management of hardware ports. Essentially, Windows has a default configuration of automatically turning off ports when they are idle.

Here’s an example of a scenario: You’re flying with your yoke or gamepad. After a few minutes, you move your mouse, either on purpose or accidentally. But Windows has suspended power to the mouse port, and there is a lag while the mouse/Windows wakes up the port. Meanwhile, MSFS appears to freeze, but it’s actually waiting for an input that is late or maybe even never coming. The results depend on your mix of OS , hardware and device (multiple variables), so it appears the incidents are random and inconsistent.

I resolved this issue by opening Windows Device Manager and unchecking the power management box in every USB, WiFi and Bluetooth item that has a power management tab. It does not change configuration or functionality of those items. I’ve had zero freezes since then.

I provided a long-winded, oops, I mean detailed explanation in this post:

I think I may have cracked the long freezes - though this may not be applicable to everyone.

I swapped out my broadband connection (approx 18Mbps) for hotspotting from a 4g phone that was getting data speeds of 30-70Mbps, but mostly around 40Mbps. I used the showcase camera over Heathrow and central London for around 40 minutes


  • Although FS FPS counter constantly says ‘mainthread limited’, Open Hardware Monitor shows that none of my CPU cores was running at more than 80%. I probably don’t properly understand the meaning of ‘mainthread limited’ so I’m probably looking at the wrong metric. If anybody wants to help me out here I’d be very grateful
  • My GPU was running at 100% main core load when I was moving, and even on menu screens (why there I have no idea)
  • London - even at the speeds I was getting the photogrammetrry took a while to resolve. When it finally did resolve, it was better than I have experienced - you could make out shop logos (Boots, Next, Currys-PC World etc. on the Strand)


  • Flight Simulator needs a sh*t load of bandwidth to run properly. Areas like Manhattan are I suspect part of in the main download and stored locally, which is what makes the download so huge (no other flight sim comes near this so where do all the extra GB go - locally installed photogrammetry scenery!). This explains why the people are having much better experiences with visuals in Manhattan than London.

I think the freezes are akin to other streaming services that buffer. Downloading high density or photogrammetry areas that you fly over a lot therefore makes sense unless you are on 70 Mbps+ broadband. Unfortunately the ability to do this is currently broken in FS.

  • London is not as bad as I thought

FS launched with 341 Photogrammetry areas but is is not clear which got installed locally and which, like London, get streamed. Giving more install options would allow users to not select photogrammetry for places they have no intention of ever going to and reduce the game’s large and ever expanding storage footprint. If they ever end up there, just accept whatever gets streamed depending on your bandwidth.

Hope this helps someone. I’ll be back with my tail between my legs next time it freezes and I’m running 4g for streaming :slight_smile:

Aside from my reply below this seems very plausible. I am tempted to turn power management off immediately but I’ll wait to see if I get anymore freezes with 4g connectivity that is over twice as fast as what I was getting. If I do I’ll know the time I spent testing and composing the post below were a total waste of half a morning!

MSFS is like a high-performance car - it takes a lot of tweaking to get the most out of it.

Additional note: Turning off power management for ports in most (all?) contemporary PCs should have no effect on any operational functions, except to prevent unpleasant surprises when the PC turns off ports with no notice and no notification. It was a concept that made sense when machines were low powered and conserving every electron of power was important.

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