Agreed… this seems like a game breaking bug that’s worthy of a hotfix when ready…. It would be very disappointing if we have to wait months for SU4 to get this fixed.
3 Likes
Can we please keep the discussion in this thread focussed on the degradation over time? I’m seeing too many post about the control menu stuff, which is a different issue. One that is frankly at best a mild inconvenience, since it is very easy to avoid and workaround, while the degradation over time really makes it impossible to fly long flights at the moment.
10 Likes
That’s exactly what I’m worried about. That’s why I moved back to 2020.
2 Likes
I am on the latest driver
From my knowledge, it just means the post has over 180 votes so its been ‘noted’ by the system. Not that the dev team has reciprocated the issue and is working on it,
.
The bug logged tag has nothing to do with the number of votes being over 180, it’s to do with whether it has been reproduced by Asobo or not. Official explanation below and as proof, here’s a bug logged topic with 16 votes:
SU16 - Reproducible CTD over NZ South Island with NZ POIs and DX12
A Community Feedback is logged in our database, and our test team is working to reproduce the issue.
Note: If the feedback is verified as a bug, the thread’s tag will be changed for “Bug logged”
The issue reported by the community has been successfully reproduced by our test team and turned into an official bug. The bug is now being assigned, prioritized, and worked on for a future fix.
7 Likes
I agree that its now been mentioned enough however it is also important that it was mentioned because it could be related and help the devs to troubleshoot the issue to resolve both situations.
1 Like
As @EnjonUK has stated, from the Welcome to the Public Forums pegged article in the News and Announcements section of the Official Microsoft Flight Simulator category
Please find below the list of official tags we will using from now:
Note: If the feedback is verified as a bug, the thread’s tag will be changed for “Bug logged”
Unable to reproduce, need further information
A community-created workaround is available from user experience
The issue previously reported is now fixed on the current version of the SIM
3 Likes
Did a bunch of tests on this Mainthread bug. No changes to my system. i.e. no bios changes back to normal etc. but was running a vanilla sim and just with default aircraft and everything disabled that can be disabled.
Test 1. Controls menu:
Sim settings on Low end preset, render scaling 30 to make sure mainthread limited, photogrammetry off, C172 loaded into random middle of nowhere airport.
Took a screenshot after 2 mins of load in and had 60fps capped, 7.1ms mainthread, 4.0ms Manipulators, 1.7ms GTUIThread,
Opened and closed the controls menu 10x. Waited 2 mins to settle and took a screenshot, 59.3FPS, 19.4ms Mainthread, 13.4ms Manipulators, 14.9ms GTUIThread,
Repeat open & close 10x and wait 2 mins, 35.2FPS, 37.4ms MT, 28.8ms manip, 29.7ms GTUI,
Repeat, 26.4FPS, 42.5 MT, 44.2 Manip, 36 GTUI,
Repeat, 20.8FPS, 56.3 MT, 53.9 Manip, 51.9 GTUI
From here it continued to get worse but you get the gist.
Test 2: Is it just the controls menu?
Fresh restart, same location, settings plane etc.
Screenshot after 2 mins of load in was as before, back to normal.,
opened and closed weather menu, very minor changes to timings which could be attributed to the timing of screenshot.,
repeated as above and still minimal change i.e. 0.xx changes but did notice some slightly higher peaks on graph.,
conclusion, not sure if there was any effect.,
Test 3. Possible to induce high mainthread?:
Settings/Location as above but loaded in the Asobo 737. Wanted to stay away from inibuilds just in case that skewed the results.
Repeated test 2 and no difference
Tried to induce high Mainthread by teleporting to different locations in quick succession resulted in 2-3ms increase in MainThread,
Switched Photogrammetry back on Mainthread started off higher at 12.0 but that’s sort of expected.
Repeated opening and closing the weather menu same result 1-2ms increase,
Tried jumping around and didn’t have any issue.
The TL:DR is I couldn’t force the mainthread to get too high by any means other than opening and closing the controls menu from the toolbar. Even after returning to normal settings installing sceneries and aircraft again I couldn’t repeat the issue as long as the controls menu isn’t opened.
Specs : 9950X3D, 64Gb RAM, 7900XTX
3 Likes
I noticed exactly the same when ALT + TAB and putting the mouse on windows bar during 1-2 sec, gaining 30% more FPS, but I’m not able to reproduce it every time
I suggest we don’t lose focus. With SU3 the MainThread is loaded way beyond it was in the first 2 releases of SU3_Beta.
I own a i9-14900KS with NVIDIA 4070 Ti. I used to have 200 terrain 200 Object all on Ultra with no traffic of any kind and hit 70-90 FPS. (DLSS Quality). Now I struggle to reach 45 with no traffic all on High except clouds on Ultra.
I’m convinced that this is a regression.
9 Likes
same for me, before su3 everything run smoothly even at high end or ultra settings, after su3 I have huge fps problems, but ONLY when i fly in career mode and especially with boeing 737 max!!!
MSI RAIDER GE77HX 12UGS
I7-12800HX
32 gb ram
8 GB GEFORCE RTX 3070 Ti
the same with me after every single flight
I think as this issue is widespread and no hotfix has been announced, it would make sense for the team to at least acknowledge in the recent development update. If you check the one from 28th August yesterday, this issue/post (and its 259 votes) has not been included. Is there a reason for it being excluded? This issue should be dealt with prior to SU4, as I am sure most people would agree.
16 Likes
I have no words for this. This issue excist since b .23 and since then not on the bug list.
I’m tired of all this msfs24 ……. I’m out until I see it is fixed. Have a nice weekend everybody.
11 Likes
I don’t like being negative since I always supported Asobo and the development of MSFS but It’s honestly worrying that a bug that has broken many people’s sim’s hasn’t been addressed in nearly 10 days! I would expect issues like these get immediate attention.
I hope that at least with the upcoming SU4 beta we will get a fix. However, seeing it not even mentioned anywhere in the latest development update doesn’t give me much hope either.
7 Likes
This bug has ruined the sim for me completely and left me not wanting to fly anymore as it feels like a waste of time when every flight ends in massive stutters. Such a shame this is what we ended up with
18 Likes
Hi everyone,
I can fully confirm what CaptainSlow8606 described – I‘m experiencing the exact same issue (mainthread load continuously increases and never recovers), and it honestly makes it hard to enjoy starting the sim at all right now.
It’s good that this problem has been raised, but it’s very frustrating that such a severe bug, which affects so many people, has remained unresolved for almost ten days now (since around August 19th, 2025).
I would really like to ask Asobo/Microsoft to release a hotfix as soon as possible – ideally even before SU4 beta – because at the moment, this issue heavily impacts the overall experience.
Thanks to everyone else reporting this as well – hopefully, the more visibility we bring, the sooner it will be addressed.
Cheers,
Stefan
8 Likes
Flying long haul - or even some medium haul routes - has become basically impossible due to SU3. I really thought the times of Asobo breaking the entire sim in a main release (!) are long over. I was wrong
7 Likes
I’d like to add that i tested the fenix sitting at R27 at london city airport. Running ultra 4k taa etc on 7800x3d and 5090. Frame rate smooth 90. Access the camera menu via the toolbar then close it, then repeat. Fps goes down with each opening. Roughly 10x and frame rate sitting at 48 and doesn’t rise. I was also getting performance degrading on long flights since about mid way through SU3 Beta. SU2 was fine so something radically changed….for the worse
7 Likes