Can’t figure out what’s going on with performance in this build….no one else seems to be complaining much about it, but the flight can be any length. It seems to happen with jets (only been using the triple and 737). Everything is very smooth up until approach and landing…then performance tends to drop through around 15,000’. Normally getting 144 FPS, on landing it drops to 90 or lower…doesn’t sound bad till you realize this is with 4x frame gen. It’s flyable, but nowhere near what it was using SU2. Feel like I’m going crazy, anyone else having a similar problem?

Not really...  in su3 my vram usage is very high though.  But from reading forum posts SU4 is a night and day performance change.  So I think the team is already on it!

 

7 minutes ago, ryanbatc said:

Not really...  in su3 my vram usage is very high though.  But from reading forum posts SU4 is a night and day performance change.  So I think the team is already on it!

 

May I ask, are you using any rolling cache?

8 minutes ago, V1ROTA7E said:

May I ask, are you using any rolling cache?

16GB

SU3 caused nothing but problems and awful performance/stuttering for me. SU2 was fine. I’m now on the SU4 beta and haven’t looked back -  night and day indeed!

Just landed in JFK (ZSAM - KJFK) with IniBuilds A359 after 15h33 in the air, 140fps on approach, zero stutters, zero issues during the flight.

SU3 is as of now, since i'm not in the beta, the best MSFS2024 version. It just works.

It does seem that SU3 may have introduced a memory leak.

Su4 beta still has the memory leak

 

https://forums.flightsimulator.com/t/memory-usage-page-file-high-with-64gb/738484/14

Edited September 19, 2025Sep 19 by Pilot53

Think i may have finally found the culprit! Some of Mamu's stuff was installed twice. I guess he changed the file names from:

a-mamudesign-marinas
a-mamudesign-powerlines
a-mamudesign-projectlifts

to

mamudesign-marinas
mamudesign-projectlifts

 

not sure about the power lines. but just did a 2h flight with no perf degradation....I'll try adding back the powerlines and see if it makes any difference. Happy so far though, even if the overall performance isn't as good as it was!

19 hours ago, V1ROTA7E said:

no one else seems to be complaining much about it

Did you miss the large thread on Asobo forums about this?  SU3 had degrading performance from early on in the beta yet Asobo failed to listen to complaints and still released it.  I myself seen performance drop 25-50% after 60-90 mins in the Fenix.  Even when most addons disabled during tests.  Once performance goes no adjustment of settings helped.  Landing at destination could have low fps but reload in the same aircraft and airport and boom performance great again.  I have a good system with a 5090 and frame rates were dropping to TWENTY at times and that was with 3x  MFG.  SU4 Beta seems to have fixed it though it still suffers from some audio popping, again well talked about on the forums.  The Main Thread regression is bug logged which means Asobo can replicate the issue.

 

Visit Asobo post here:

https://forums.flightsimulator.com/t/mainthread-loads-up-more-and-more-and-doesnt-recover/729018

33 minutes ago, cj-ibbotson said:

Did you miss the large thread on Asobo forums about this? 

Yeah, I don’t visit that forum much anymore. 
 

thanks for the link!

50 minutes ago, cj-ibbotson said:

Did you miss the large thread on Asobo forums about this?  SU3 had degrading performance from early on in the beta yet Asobo failed to listen to complaints and still released it.  I myself seen performance drop 25-50% after 60-90 mins in the Fenix.  Even when most addons disabled during tests.  Once performance goes no adjustment of settings helped.  Landing at destination could have low fps but reload in the same aircraft and airport and boom performance great again.  I have a good system with a 5090 and frame rates were dropping to TWENTY at times and that was with 3x  MFG.  SU4 Beta seems to have fixed it though it still suffers from some audio popping, again well talked about on the forums.  The Main Thread regression is bug logged which means Asobo can replicate the issue.

 

Visit Asobo post here:

https://forums.flightsimulator.com/t/mainthread-loads-up-more-and-more-and-doesnt-recover/729018

I share that experience, and have had it happen with su4b unfortunately.  It seems to be related to memory management.  When performance really drops off I notice physical ram usage drops in half while swapfile usage increases when viewing from the dev mode fps counter.

I have same degrade experience in SU3. worst in Europe. 

Michael Moe 

On 9/19/2025 at 4:58 PM, cj-ibbotson said:

Did you miss the large thread on Asobo forums about this?  SU3 had degrading performance from early on in the beta yet Asobo failed to listen to complaints and still released it.  I myself seen performance drop 25-50% after 60-90 mins in the Fenix.  Even when most addons disabled during tests.  Once performance goes no adjustment of settings helped.  Landing at destination could have low fps but reload in the same aircraft and airport and boom performance great again.  I have a good system with a 5090 and frame rates were dropping to TWENTY at times and that was with 3x  MFG.  SU4 Beta seems to have fixed it though it still suffers from some audio popping, again well talked about on the forums.  The Main Thread regression is bug logged which means Asobo can replicate the issue.

 

Visit Asobo post here:

https://forums.flightsimulator.com/t/mainthread-loads-up-more-and-more-and-doesnt-recover/729018

1000% foreign here in any plane including Fenix.  I frequently do 2-3.5h flights and never see this issue, at 2x NV DLSS FG.

I can confirm that behaviour with SU3.

120 fps when i start a flight in Frankfurt with plenty of aircraft, 30 fps when i land somewhere with my Fenix, beeing nearly alone there.

When im standing at the gate, i cant even turn external camera anymore because of stuttering.