Not a solution regarding CTDs and low GPU performance/limited by main thread on higher end CPU's - Enable all CPU cores in Windows!

Disclaimer
As pointed out first by FoundHaddock891, the suggested solution in the story below can not work. However my system works now. While there is a reason for that I do not have any clue. Do not play around with this setting as reverting it does not bring change.
I do advise to update your community content and keep your system in a good shape as per drivers and windows and so on. Although I did not change anything else in my system I have maintained the game, community content and Windows. I have no control over changes on that end. So it must be something else that prevents it from crashing now and gives me this unexperienced stability and performance. Peace.

Hi everyone!

Plagued by CTDs with my new AMD card to a point at which it was unplayable, I started investigating. I got to a point at which I would have loved to return my new AMD RX 6900 XT and buy myself a car for it. Little did I know!

System:
My system specs:
Rio Toro Enigma G2 850W
MSI MEG ACE Z390
64GB dual channel Kingston KHX3600C18D4/32GX(currently running XMP2 3GHz@CAS16)
Crucial CT1000P1SSD8 (M.2 NVMe SSD) for system
a mix of SATA HDDs and SSDs for storage

GPUs tested on this system:
MSI RTX 3090 Gaming X Trio
Gigabyte RTX 2080 Ti Windforce (not the OC version but a whopping 120 MHz auto overclock on air cooling)
XFX RX 6900 XT

Anamnesis:
unusually restraining mainthread. one core constantly maxed out thus limiting graphics options.
tons of CTDs with AMDs card yet not with Nvidiaā€™s super consistent driver.

So, especially with the AMD card I experienced serial errors of this kind:
Example:
FlightSimulator.exe

Summary
Stopped working

Date
ā€Ž29.ā€Ž04.ā€Ž2021 21:10

Status
Report sent

Description
Faulting Application Path: D:\SteamLibrary\steamapps\common\MicrosoftFlightSimulator\FlightSimulator.exe

Problem signature
Problem Event Name: APPCRASH
Application Name: FlightSimulator.exe
Application Version: 1.15.8.0
Application Timestamp: 00000000
Fault Module Name: VCRUNTIME140.dll
Fault Module Version: 14.28.29913.0
Fault Module Timestamp: 6041a7e8
Exception Code: c0000005

So, it is always Exception code c0000005.

Debugging with Microsoft Visual Studio reveals an application stop due to continuously attempting to write to unallocated memory. However, I have no recorded history of this.

Solution:

Restlessly looking for solutions, I stumbled upon a system option which appears useless at first sight. In msconfig.exe there is the option to reduce the number of cores recognized by Windows. By default it is unchecked. Who would like a CPU with less cores, right? In fact, enabling it unlocked my systems.

This option is not only suitable to reduce the number of cores used but you can also determine how many cores are used. So, if a previous software installation or any sort of idiotic(or particularly useful) system option has reduced this number you can just set it back to full value. Which is what I did, in an effort to make sure full reserves are available to Windows. I cannot imagine why both my systems have been configured in this way. However, by enabling all cores I seem to have fixed this issue and gained massively. I suspect, because the DX11 thread, rather one of the four or the one which maxes out, still maxes out while running MSFS but now gets less bothered by Windowsā€™ other tasks.

Application
Only discovered it last night and still testing but hereā€™s what you do:

  1. run msconfig.exe
  2. Select the Boot tab
  3. open ā€œAdvanced Optionsā€¦ā€
  4. Check ā€œNumber of processorsā€ and select ALL of them (16 for an 8-physical core i9 with HT)
  5. Reboot

Conclusion
It is a driver issue, but not as you thought. The assumption is that not all cores were enabled and available for Windows to distribute load to dynamically. The idea is that Nvidiaā€™s driver doesnā€™t estimate performance based on CPU model and cores leading to unbiased expectation in a scenario where a lower performance is delivered. Whereas AMDs driver might do this disregarding the actual core count managed by Windows.
I dare to say that the AMD driver really is a bit more elaborate and makes better use of system resources, especially cores/threads. If not all cores were used, leading to a lower performance and ultimately crashing drivers, and the vcruntime140.dll, and basically hitting out at every other running application. Like OBS, browsers, add-ons and so forth. Which I could all stabilize btw. I was unable to fix the driverā€™s exaggerated expectations thus making it the weakest link in the chain. Consequently, it was always the driver which failed and not something else.
The fact that Nvidia is less affected proves their system stability. But performance limits did not come from the Nvidia card or driver. The Nvidia driver handled the system even when handicapped without crash.
The observation is that the mainthread is performing even better with the AMD card&driver than with my old 2080Ti Nvidia card&driver installed.
I never saw 90 FPS in 21:9 1440p before. Now I do. Okay, not since I switched back to near Ultra settings. And I never saw 90 FPS in the big cities. But this is what youā€™d expect. However, now my GPU determines the rate at which I go most of the time. I have high hopes that this might keep the system from running into trouble with memory allocation and CTDs as these are essentially multitasking errors caused by a lack of system resources.
My observation matches the experience other people made, that AMDā€™s cards are performing better in low-end systems. Essentially, it is exactly what we are looking at in MSFS. Itā€™s a CPU bound scenario in the more stressful areas of the model planet. Especially when you are running a different count of CPU cores than actually present. As this number can only be lower.

I am expecting this check-up to appear on the troubleshooting page on MSFSā€™ zendesk soon.

edit: now testing different XMP profiles for my memory again but only to optimize performance before even considering overclocking

Cheers!

What are you using to measure your FPS?
Did you have any on the instrument views popped out at the time?

i never bothered to disable the steam overlay after finding out that it has minimal effect if any. but i refer to the readings of the in-built tool. i find it quite appropriate to set the system up tbh.

i do not pop out instruments in favour of higher FPS in the main window

I have only played 2 times 5 minutes since 1.15.8.0, without even waiting for a CTD.
But then you made me want to get back to it. I just made the setting in MSCONFIG, I only had one core activated.

please keep us up to date!

No dice. While Iā€™ve seen CPU utilization improved, I just tried a 1.5 hr flight and got a CTD 45 min in. Same as usual.

This setting is only used for diagnostics and is only useful for ā€˜limitingā€™ the number of cores. If you leave this option unticked, then windows will default to using all of your cores anyway. You can tell because if you are limiting the number of cores via this manual override, then this will show in the task manager with the corresponding number of cores shown. So in short chaps, sorry this is a total red herring.

6 Likes

As plausible as your explanation appears. It appears to be the only change I made since testing the 6900 last time. I am even using the very same driver.

What kind of system are you trying to run? also resolution.

Ryzen 5 3600X
Radeon RX 5700XT
32GB 3600 Ram
B450 Tomahawk Max
M.2 NVME
200mbps

1440p high settings. CPU stays at around 30%, GPU at 65%, RAM at 50%, and VRAM at 70%. Iā€™ve capped my fps at 30. I get 45 - 50fps when capped at 60.

Everything ran perfectly fine until February, when a lot of people started having problems. Iā€™ve never suffered from any of the other issues people had been complaining about. Iā€™m not convinced itā€™s on the users end. Itā€™s completely random to who it affects. AMD, Nvidia, Intel, 16GB or 128GB of ram, 20mbps or gigabit fiber, HDD or NVME, itā€™s not hardware specific. One 3rd party aircraft developer stated either here on the forum or in a FB comment that he hasnā€™t been affected, but a few of the other developers on their team are, with no evidence to determine why some were, and some werenā€™t. After seeing hundreds various things people have tried with a 0% success rate, I think Asobo and Microsoft will have to be the ones to figure it out. Thereā€™s a reason itā€™s quickly made itā€™s way to the top 3 on the feedback snapshot. Iā€™m hoping for a miracle with the upcoming Sim Update, but Iā€™m keeping my expectations low, as Iā€™ve been underwhelmed by the past few Sim Updates. (Iā€™m not hating on MSFS by any means. Itā€™s still my favorite sim.)

Yes, I canā€™t explain that at all. I do wish you all the best in fixing whatever it is underlying here.

I guess I can go enjoy my red herring now. Whatever. It works for me. Surprising but positive. Good luck everybody.

Not sure if this will help you, but I had the same problem, CTD around the 45min mark, what I found was that I just kept reducing the AI air traffic, now I fly GA aircraft so after trial and error the sweet spot for me was to set Airliner AI to around 5 % and GA to around 35%. I started at 50% and kept reducing it till no more CTD.

Thanks for the info.

I changed my msconfig but it made no difference.

I was worried about changing it back but Iā€™ll just leave it like it is set.

I recommend setting it to the default (unchecked), otherwise you might at some point run into other issues and will search forever to find this again.
Technically no reason to enable it for the regular users and whatever caused the observation provided in the OP was surely not this setting.

3 Likes

Thanks, will do.

1 Like

I gave this a shot and had a CTD shortly after takeoff. Oh well.

@JerryWeirdspeed
Please change your Title for this Topic.
It is not a Possible Solution.

1 Like

You, sir, are right.

1 Like

In spite of all the negative replies you have received, I wanted to thank you for reporting your observations. Thinking outside the box can have itā€™s advantages.

6 Likes