Awful performance on su3 beta 1.5.19.0

Sim Update 3 Beta | MSFS 2024 Install, Performance & Graphics
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ISSUE DESCRIPTION

Description of the issue:

Did you experience this issue before you joined the Beta?
Performance on su2 started out great after launch but overtime got worse and worse.

[PC Only] Did you remove all your community mods/add-ons? If yes, are you still experiencing the issue?
Yes, I even reinstalled windows twice and changed graphics cards from a 4080 super to a 7900xtx and still performance is awful. The previous beta build prior to 23/07 had overall amazing performance.

FREQUENCY OF ISSUE

How often does this occur for you (Example: Just once, every time on sim load, intermittently)?
All the time.

REPRODUCTION STEPS

Please list clear steps you took in order to help our test team reproduce the same issue:

  1. Load the sim
  2. Enable in game performance overlay
  3. You will notice that in the game menu fps is sky high, up to 200 fps
  4. Start a flight using any aircraft
  5. As soon as you hit fly the fps will drop like a stone. Once the flight fully loads I struggle to get over 60 fps, even using a Cessna 172 at a deserted airport. On the previous beta build I would get over 120 fps or even more
  6. Do not make this current build your release candidate. Performance is atrocious

YOUR SETTINGS

If the issue still occurs with no mods and add-ons, please continue to report your issue. If not, please move this post to the User Support Hub.

What peripherals are you using, if relevant:
Tflight hotas one, turtle beach rudder pedals

[PC Only] Are you using Developer Mode or have you made any changes to it?
Yes but I only use it for the performance overlay

[PC Only] Many issues may be due to an outdated graphics card. Please state your Graphics Card Driver Manufacturer (NVIDIA, Intel, AMD) and Version:
I have tried 2. The first was a gigabyte 4080 super and the second was a sapphire nitro + 7900xtx

[PC Only] What other relevant PC specs can you share?

MEDIA

Screenshot 2025-07-25 151456
Screenshot 2025-07-25 1514561920×1085 232 KB

Please add a screenshot or video of the issue occurring.

[END OF FIRST USER REPORT]

:loudspeaker: For anyone who wants to contribute on this issue, Click on the button below to use this template:

Do you have the same issue if you follow the OP’s steps to reproduce it?
•

Provide extra information to complete the original description of the issue:
•

If relevant, provide additional screenshots/video:
•

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Just to make sure: do you have an empty Community folder?
Looks very much alike a problem I had: main-thread was hammered, causing fps to be stuck at 60ish fps(2xFG), no matter what.
For me it was //42’s Campout causing major problems…

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I did have a clear community folder when I reported this. Since then I have downloaded my addons. Earlier I went into the sim and performance had improves but I have just started a flight and performance has tanked again. Just to reiterate, the previous beta build had amazing performance for me

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This is all I have in my community folder. On the previous beta build I had even more

fsdreamteam-gsx-pro
fsdreamteam-gsx-world-of-jetways
fsltl-traffic-base
ifly-aircraft-737max8
ifly-aircraft-Data
ifly737max8-RYR-EIHETAL
ifly737max8-RYR-EIHMSAL
ifly737max8-RYR-EIIFXAL
ifly737max8-RYR-EIIGLAL
ifly737max8-RYR-EIIJGAL
ifly737max8-RYR-EIIKJAL
inibuilds-airport-eggw-luton
mobiflight-event-module
orbx-volanta-aerocaches
panel-raas
papadelta-epsc
pmdg-aircraft-77er
pmdg-aircraft-77er-liveries
pmdg-aircraft-77f
pmdg-aircraft-77w
scenerytr-airport-ltfm-istanbul
tms-airport-egcc-manchester

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I highly doubt that you truly ever achieved 120FPS while flying in this sim in some previous version even though it’s what was represented. You might get that kind of number in some FPS game but it seems to me to be wildly unexpected in any flight simulator software. Many of us in mid-range systems would die for FPS around 60. Could it have simply been that the performance overlay in your previous version was incorrect? How has your smoothness been affected? Are you running with multiple monitors or trying VR? I think, given this is not just some game but a highly complex real world flight simulator, we are too obsessed with FPS and getting an immersive, smooth flight needs to remain our goal.

1 Like
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Firstly, I am not obsessed with FPS but it does give an indication of how smooth the sim is running. I simply mentioned my FPS in the original post to give an indication of the performance drop I have experienced. My sim has gone from super smooth to extremely stuttery in a matter of days and the only thing that has changed is the new beta build on the 23rd

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Getting high FPS helps with having an immersive smooth flight, especially since it means you can set a smooth FPS cap.

2 Likes
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Here is an example of the ifly 737 max at the default handcrafted Cork airport

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Try again after turning developer mode off. The fps overlay will still stay on.

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Do you have the same issue if you follow the OP’s steps to reproduce it?
• I’ve done extensive testing comparing SU2 and SU3 throughout the time SU3 Beta has been available, and I get HALF the performance in SU3 as I do in SU2. I have been avoiding the beta mostly because of this. I have removed all add-ons, cleared all caches, and used the same plane/testing criteria when comparing the two. Something on the CPU side is limiting the frame rate way more in SU3 than it does in SU2.

Provide extra information to complete the original description of the issue:
• I spent hours last night testing 1.5.19 vs. 1.4.20 and here are screenshots showing my FPS is literally half in SU3. Same plane, locations, and settings. I have my render scaling set to 30% on purpose to make sure the CPU is the bottleneck for each of the tests. Something on the CPU side is causing SU3 to have horrible performance, and it worries me that SU3 might be released soon. I’m testing with a 9950X3D and RTX 5090 FE.

The MainThread and rdrThread latency in SU3 is 10-12ms. In SU2, it’s It’s 4-7ms.

If relevant, provide additional screenshots/video:

Sim Update 3:

01_su3-30percent-render-scale
01_su3-30percent-render-scale1318×873 58.7 KB

Sim Update 2:

02_su2-30percent-render-scale
02_su2-30percent-render-scale1277×859 59.8 KB

Sim Update 2 before enabling Process Lasso:

03_su2-process-lasso-off
03_su2-process-lasso-off1416×883 65 KB

Sim Update 2 after enabling Process Lasso (forcing MSFS exclusively onto my CPU’s CCD0):

04_su2-process-lasso-on
04_su2-process-lasso-on1221×815 51.7 KB
4 Likes
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I’ve seen all the arguments against Process Lasso. And for single CCD AMD CPU’s it’s marginally effective. But for CPU’s like your 9950X3D and my 7950XD3 it’s undeniably as close to being a ‘must have’ as anything can be. I’ve done a lot of testing, and with the sim, and only the sim (except for a few core Windows processes that shouldn’t be touched) running on CCD0, with everything else assigned to CCD1, I definitely see a benefit.

Try setting all Windows process priorities (again, except for the core processes) to ‘Idle’. You might think it’s a bad idea, but Windows processes simply don’t need high (i.e. Normal) priorities.

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What affect would that have?

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It has been documented by several folks that leaving the developer mode on can cause significant performance issues beyond the normal issues the sim has. I found this to be true as well. And, since you can still see the fps counter with it off it’s the best practice.

1 Like
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You need to turn it off in devmode, otherwise it stays.

But your observation would pair with my hypophisis about the CoherentGT.dll which may have a memory leak at the moment.

maybe it is worth for Asobo to take the hint, if that may be the cause.

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Ok thanks. To be honest, on the previous beta build I had amazing performance while leaving on the dev options but I hear what you are saying and I will turn them off. It’s just a bit of a ball ache having to go back into settings to turn off the overlay when not needed :laughing:
One other thing that I am only noticing now, my VRAM allocation is much lower than it usually is. I know other processes are allocated VRAM but I usually have around 22 GB showing available when using MSFS. In my video it is down to 18 GB, a drop in what I would expect that I have also experienced while using my previous 4080S. When this happens I inevitably have performance issues. I wonder what is causing this as after a restart of the sim this usually is resolved and my VRAM bumps back up to the usually 22 GB that I would expect

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Another example of poor performance. It seems to tank whenever you are in an interior view such as a wing or engine view

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Like most other people here, I’ve been having problems with the beta versions. So I decided enough was enough and nuked my windows 11 install and started afresh. I had made a few changes to my hardware and thought it might be a good idea to start again.

It certainly helps that fs24 doesn’t take hours to install like 2020.

Interestingly after doing this, the sim is almost unrecognisable now. I’ve NEVER had a smoother experience with fs24 as I am now seeing. Also many graphical anomalies I was having with the latest Nvidia drivers have vanished. The sim loads up in about 30 seconds now too, even with many items in my community folder.

I’ll admit I was beginning to lose hope in fs24 ever being properly usable, but even on my mediocre pc the performance is stellar.

For reference I’m using a 9700k @ 5Ghz, RTX 3060 12GB GPU, 32 GB @ 3200MT/s Corsair vengeance RAM.
Windows 11 on Samsung nvme
Sim is on separate Samsung 980 nvme
HDR on
4k with dlss performance mode
High preset with shadows and reflections on medium
Ray Traced Shadows on
Dynamic settings off
Frame rate set at 30
AMD FG x2 on
Hags on (might try with it off later)
ReBar off

4 Likes
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I performed a reinstall too but the 1.5.19.0 beta update is performing terribly. Give me back 1.4.20!!

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how in gods name are you even getting 60FPS?

I have 9800x3d and a 5080 and barely get 30…

1 Like
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Craig, I agree it is a bit of a pain, but it did help me to turn it off. And like everything else the issue with Dev mode on was transient and arbitrary. As for the VRAM, yeah I get it. I went from a 12g 3080 to a 16g 5070ti hoping for enough VRAM. But, it falls short at times. The only thing I found to help was to turn off Resizable Bar (REBAR) in the BIOS. Saves from 1.5 to 2 gb of VRAM. There is a quite lengthy thread about that. Seems to help probably 90% of the folks posting in that thread. I’ve tested extensively and it doesn’t seem to impact performance at all for me by turning it off. Of course if you do, other games or whatever that rely on REBAR could be impacted, so YMMV. I have also noted at times the inside view hits my mainthread harder than external view which is mind blowing. I don’t know why this happens. Anyway, best of luck. Lots of folks on here that suffer the same, so hang in there. 2020 runs flawlessly for the most part for me (live traffic sometimes hits hard just like in 24). My CPU is a 9800x3d.