MSFS2024 huge performance issues since NVidia version 591.44 with BIOS Resizeable BAR enabled

User Support Hub Install, Performance & Graphics
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ISSUE DESCRIPTION

Until NVidia version 581.80 everything was working perfect for me. I have a high end PC:

  • GeForce 5070ti
  • i7
  • 32GB RAM

And the performance was really smooth with SU4.

Starting with driver version 591.44 and all subsequent ones, I have severe performance problems. I understand it’s not a PC capacity issue or wrong settings, as it works perfect with 581.80 everytime I roll back to this version. Everytime I try to upgrade to newer version I have problems, then I roll back to 581.80 and it works perfect.

With the newest versions, the flight starts fine with very good performance around 60FPS. At some point, the frames start dropping and they get below 20FPS. And if I try to move the view there’s a lot of stutters.

When I upgrade the driver version, I always delete shader cache, recreate the rolling cache, and delete all NVidia temp folders. I also tried using DDU to fully uninstall previous driver version, and same results.

FREQUENCY OF ISSUE

100% of the times I try to fly with these versions of the driver

REPRODUCTION STEPS

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

  1. Install an NVidia version higher than 581.80

  2. Try to fly a career mission mainly with stock iniBuilds A320 and A321.

  3. After some time (usually it starts even during preparation before initiating the taxi), it starts dropping FPS and starts stuttering

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: Just a keyboard, a mouse and TurtleBeach Velocity one joystick.

[PC Only] Are you using Developer Mode or have you made any changes to it? No

[PC, MSFS 2020 Only] Are you using DX11 or DX12?

[PC Only] What GPU (Graphics Card) do you use?

Nvidia RTX 5070ti

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

i7 with 35GB RAM

MEDIA

Please add a screenshot or video of the issue occurring.

2

Confirmed here. I thought i was imagining. Updated the driver to latest 591.44. Started the flight and saw stutter when panning. I have always set Frame Gen to x3 from the NVIDA app, and sim has been smooth as butter. So i started checking dev mode and realize that the mainthread is completely saturated at 50ms! FYI, my settting hasn’t changed, and on the prior drivers, my main thread is around 10-20ms when using Frame gen x3 (override from Nvidia app) and with V-sync enable from nvidia app. My monitor is 60hz so fps is always solid at 60. Now it is completely in the red. So something is wrong with the way framegen work with new driver.

also, when i tried rolling back to previous driver, the issue still persist! Even DDU the driver and reinstalled it fresh. I have to roll all the way back to 577.00 for it to work normally again.

my setup:

5800X3D

5060ti 16GB

64GB RAM

Win 11.

Please check.

1 Like
3

So not sure if Nvdia has retroactively changed something from prior drivers. Might be worth for the team to look into this.

4

You are not on latest driver or made a typo. Latest driver version is 591.74.

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I am on latest version and do not see any performance issues. Maybe try a clean driver reinstall with DDU.

5

In my case I tried all, including 591.74, and all of them starting at 591.44 have the same problem for me. I tried everything, including DDU in safe mode, and same results always.

I might be related with specific aircraft, as I’m mainly using the stock iniBuilds A320 and A321, don’t know, but it’s impossible to upgrade the driver.

6

I think I found the problem. I had the “Resizeable BAR” option enabled in my BIOS. The PC is quite new, I got it like 2 months ago, and I was not even aware that this option was enabled by default.

I disabled it, and now even with the latest NVIDIA driver everything works perfect, and the performance is the same or even better than with 581.80 version.

Looks like this setting didn’t affect the previous driver version, but it does with the latest.

Thought of sharing my solution here in case it happens to somebody else.

1 Like
7

Moved to User Support Hub since not a bug with MSFS.

8

That is a strange coincidence. But if it works for you it is fine.
Here is some background why resizable bar may not be the culprit and why it may cause issues when deactivating it.

Resizable bar usually performs better. I know in the MSFS forums there are discussions from time to time that this feature may effect performance but a definitive evidence is still not presented.
And if one know what resizable bar does will even wonder more: resizable bar is a PCIe/GPU feature allowing the CPU to write more data with one write request to the GPU. Without resizable bar the CPU can only write a maximum of 256MB to the GPU memory in one go. With resizable bar this is unlimited. So the CPU has a lot less to do when writing huge data junks to the GPU because the bus DMA controller handles the rest.
But I would be careful to disable this feature since it may have negative impact on other games.
This is the reason why most MB vendors and specifically for high end MBs activate resizable bar per default. So a new PC with this feature enabled is not uncommon.

Edit: I have resizable bar enabled (of course) and do not see any negative impact - when deactivating it the performance is slightly worse.
I have a 9800X3D, an Asus crossbar x870e hero motherboard, 96GB of 6000MT/s CL30 memory and a factory overclocked RTX5090

Edit2: one thing came into my mind which can cause issues with resizable bar on: check if your GPU (with GPUz for instance) is using all 16 PCIe lanes. If not this can cause issues when transferring big amounts of data. If it is less then 16x you might have shared your primary bus with most likely a PCIe NVMe → check you MB configuration in that case.

2 Likes
9

Thanks a lot for this valuable info, actually I just read that a possible reason for the GPU to use less than 16 PCI lanes is the use of a secondary M2 SSD disk, which is my case.

I just ran the GPU-Z utility which I didn’t know, and it says I’m running on the 16 lanes (@ x16 5.0)

But I’ll keep investigating, maybe this secondary disk is somehow interferring.

10

Ok, at least we now know that the GPU is connected correctly and does not share any PCIe lanes with other devices.

The dependency to the resizeable bar is still strange.

It would be interesting to have some telemetry of the frametimes of MSFS2024. Can you enable the frame counter display via the developer mode in MSFS and run MSFS again with resizable bar (where you see the stutters) and look at the frame times: is the GPU stalling or is the main thread (CPU) stalling?
If it is truely resizable bar related, I would expect to see the GPU frame time spiking.

11

After reading some threads in Internet I saw that my MB BIOS was from May 2025, and it was recommended to update it, so I just went ahead and updated the BIOS with the latest version, it’s an Asus prime z790-p wifi. The latest version comes with some “performance and stability improvements” and more devices compatibility.

After this update, I’ve done a couple of quick tests with Resizeable BAR enabled and everything was perfect and smooth. These kind of tests always failed before this update.

I’ll still do some complete flights before claiming victory, but looks like it was due to a problem with the BIOS version of the MB.

Thanks a lot @WildTapestry269 for all your hints and interest, really appreciate it.

Will keep here posted with more details if I find something interesting, as this might be useful for others with similar issues in the future.

2 Likes
12

Perfect :+1:

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BTW, yes, while having the issue, I observed that CPU was spiking when I got huge stutters, it went up from around 12%-20% to 64% or even more.

14

3 posts were merged into an existing topic: RTX 5060 Ti 16GB or RTX 5070 12GB?

15

so it´s always the better option to disable resizable bar?

16

I mean the post above you from the same person says resizable bar is fine.

17

I disabled it today and it was quite beneficial … but could be due to other reasons as well. it´s such a multifaceted thing

18

make sure your BIOS is up to date

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yes. when the used machine arrived BIOS was from June 2025, updating it to the March version has been pretty substantial

1 Like