Coherent GT and Performance decreasing during flight

I have a drastically FPS reduction in flight… (Especially in long flight)
BUT CPU and GPU are not stressed.

Settings FHD, High End.
(same behavior with many settings in ULTRA)

Do you have any add-ons in your Community folder? If yes, please remove and retest before posting.

I will test it

Are you using Developer Mode or made changes in it?

Only now for testing porpouse.
But same in normal mode.

Brief description of the issue:

Check the screeshot.
Low FPS (that often they reduce during the flight) with not stressed computer.

Provide Screenshot(s)/video(s) of the issue encountered:

Done it

Detail steps to reproduce the issue encountered:

PC specs for those who want to assist (if not entered in your profile)

i7 8565U
External GPU - Radeon RX590
(at the begin of the flight - at the ground - I have more than 20/fps and GPU 100%)

Build Version # when you first started experiencing this issue:

Actual (issues started after stuttered correction patch)

Are you on the Steam or Microsoft Store version?


Did you submit this to Zendesk? If so, what is your ticket #?

Not yet.

You and me both. Interestingly enough, the sim also tells me that i’m limited by CoherentGTDraw. I’m not sure if this has something to do with it.

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I am having the same issue since the beginning. After 1 hour in flight, the fps gets low by itself.


It does not even need a flight. Yesterday i experimented with having MSFS running throughout the day sitting on the ground in a default aircraft and default airfield with no community mods. What i found is that MSFS causes a slow loss of frames rates with no impact or change on CPU/GPU/VRAM. I started with a FPS of 42 and over a 12 hour period ended with a FPS of 9. Now i did absolutely nothing on MSFS and there was nothing else running on the computer. The degradation was first noted at the 3 hour mark with the first drop of only 2 FPS but it slowly got worse each hour.


This has started happening to me too recently, about an hour into the flight it drops to about 10fps


Very interesting observation.

The worst part is that I start with a good frame rate, limited by my GPU at 100%, but as the time passes it decreases and at the same time the GPU usage decreases.
A few days ago, I finished a flight with 3fps and GPU under 10% …

Opened zendesk ticket
Request #107644

I hope that they will consider it.
Please if someone have experience with this problem, ad them his consideration, and vote the bug.

I had exactly the same problem, due to the last updates I was so angry with the performance that I dared a try and reinstalled my entire system, installed win 10 ISO with 21H2 update, the latest drivers and GPU with MSI Overclocker automatically overclocked, MSFS installed and after that I had no more problems and there were no more problems during the flight from now on. From OMDB to EDDL, the FPS remained stable, the mini legs when reloading the scenery have become significantly fewer, but with RTX 2080 with the Fly By wire 320 it runs partially stable over 40fps, during the approach in EDDL the fps on the ground between 27-32fps which is absolutely acceptable, GPU utilization permanently in the air at 99%, on the ground around 70% ( i simulate on High , 3840x1080 Ultra Wide 100% Resolution , Ryzen 9 3900x 32gb 3200Mhz RAM )

Yesterday I completed a 3.5H Flight with WT-CJ4 and I had no issues.
I do not understand under which condition the problem happen…

I notice the start of this behavior at the begin of May just after a patch against the stuttering issues.

@derDonX If you do start having issues, turn this (and any CPU overclocks) off first. I know from personal experience that they do cause CDTs, and likewise, turning them off solves them. It’s equally true that overclocks do not help your MSFS performance in the first place, so I’d turn them off and leave them that way, unless you play other games when they may help.

I actually do that on a regular basis, except that I do the kind that doesn’t mess with your files or programs. Other than taking longer than I’d like, and rebooting without any warning that has caused me to lose posts on Chrome (including one to this forum, I think), it works great, and it’s always nice to have a fresh copy of Winders on your system. But I wonder if the “leave files and apps” intact kind of reinstall will be as helpful as the “complete reinstall from scratch” is?

Now, having said that, if a reinstall of MSFS from scratch will help me as much as it has you, well, then it’s just a matter of when can I do it, not if.

Any thoughts on this?


Today after WU5 (and just departed from OSLO)
TBM930 with WT G3000 Mod.

Switching off panels mitigate the problem…
(But it cannot be a solution…)

Found an old interesting video…

(2) Microsoft Flight Simulator 2020 coherent GT draw poor performance video demo 2 - YouTube

I’m moving out in selective way the add-on.
Without add-on it seems the issue does not appear.

Anyway test in progress…

New Update.
For Airplanes with G3000 (I use the WT Modded), the issue seems the “roaddata” package.
Without it the problem seems a lot mitigated.

After other test the issue is still not well identified
Test in progress

tengo el mismo problema desde hace dos dias, solo en vuelos largos. Tengo i7 8086K CPU 32GB Radeon RX6800XT (en puerta tengo 60 fps GPU 100% y va disminuyendo a 7 fps y se cuelga enviándome al escritorio.

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Vuelo con Airbus 320Neo de FlybyWire.

Actual situation