Latency and Stutters on SU13 Beta

Bug Reporting Hub Resolved
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While I was excited to get my new PC up and running for Microsoft Flight Simulator, that excitement was cut short once Sim Update 13 Beta was installed.

As a tech support specialist and developer for a leading manufacturer of flight simulation hardware, I have to keep up to date with the two leading flight simulation titles, which includes beta releases. Sim Update 13 Beta, from a performance standpoint, is an absolute hot mess, even with cutting edge PC hardware. Let me explain.

Since installing SU13 Beta, from the initial loading of the Xbox Games Studio screen all the way to the menu, Microsoft Flight Simulator exhibits regular and consistent micro stutters and latency spikes (latency spikes are viewable from the Nvidia Performance Overlay as Average PC Latency). In the menu, these spikes and stutters increase in frequency, sometimes rendering mouse movement and menu object selection impossible until the latency and stutters subside.

Once I am actually in the simulator session, the stutters and latency spikes only continue and in some cases get worse. Typically the PC latency reported by the Nvidia Performance Overlay during the stuttering event is between 98-157MS, On the longest pauses I have seen the latency go as high as 357MS. These pauses render camera movement and cockpit interaction useless as well. My average reported latency with SU12 is 42MS from the Nvidia Performance Overlay/

With the Devmode FPS counter in view, these pauses primarily come from the MainThread readout, but during the worst ones have seen them hit the Manipulators and CoherentGTUIThread.

These latency spikes are persistent regardless of running the simulator in DX11 or DX12, with graphics settings on low or ultra, and regardless whether my community folder is populated or empty. I have gone through every iteration of known fix for stutters and procedure for updating to a beta Sim Update.

The only resolution I have at this time is to rollback the sim to SU12. That completely solves the issue of stuttering and latency spikes and the simulator runs flawlessly. Hopefully a future build of Sim Update 13 Beta will provide a resolution.

For reference, the system is a brand new build. Less than a week old.

System Specs:
AMD 7950X3D (3D V-Cache enabled for MSFS)
Asus ROG Crosshair X670E Hero BIOS ver. 1602
64GB G.Skill DDR5-6000 RAM CL30 (2x 32GB)
MSI Gaming X Trio RTX4090
1x Samsung 980 Pro 1TB NVMe SSD
2x Samsung 980 Pro 2TB NVMe SSD
Windows 11 22H2 build 22621.2134
Samsung Odyssey Neo G9 5120x1440

I have included a short video of the stutters and latency spikes on my system with SU13 Beta.

https://youtu.be/-UB4lYGmb54?si=o5I4aa_deDz4-Lt1

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Your video shows very clearly your issue. However I’ve got to say I’m getting the same if not better performance between release and beta version and certainly not observing the spikes you see on panning. System specs 12700K@5ghz/RTX 4090/4K/ultra settings/30fps/30hz/vsync/DX12. This must mean the issue cannot be attributed totally to any code changes Asobo have made between versions but must be due to a difference in settings and/or hardware between your and my systems. I know you shouldn’t need to do this but as Asobo don’t have access to your system the onus is on you to identify the cause. Yes this must be annoying for you as you didn’t change anything other than the beta! Whether yours has the ‘problem’ causing setting or mine doesn’t see the problem as I have that setting different would be interesting to see :slight_smile:

I have always used vsync since fsx days. Perhaps this is the smoking gun. Have you tried (even just for a test) to set this to 1/2 refresh rate with monitor at 60hz? Or 30hz with normal vsync if your monitor supports that? This gives the system some overhead for situations where texture/mesh loading is above average such as panning past airport buildings etc.

Edited to add declaration: I do see the occasional stutter on panning and have done since the sim was released and no worse in this beta but once the attributes causing the stutter are loaded in memory I can pan past again with no stutter.

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3

@CarbonSpark9321 I’m getting a ‘this video is private’ message on Youtube.

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Video link changed from private to unlisted, so you should be able to view it now.

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5

After reading your suggestions I have gone back and re-installed SU13 Beta.

My monitor supports 60,120, and 240Hz refresh rates. During the video I had it set to 120, normally I have this on 240. I have also been running G-Sync on this monitor as it is a G-Sync display as well.

I have done the following on this last test with SU13 Beta:

  • Disabled G-Sync
  • Set the monitor to 60Hz
  • Disabled HDR
  • Switched to the Low-End preset in MSFS
  • Disabled any anti-aliasing
  • V-Sync On with 50% Monitor Refresh Rate
  • Deleted the Nvidia Shader Cache
  • Disabled the 3D V-Cache for the 7950X3D
  • Ensured that no Nvidia driver adjustments were applied Globally and for MSFS.

I have essentially stripped the simulator back down to a bog standard install that a potato could run.

I still get a latency spikes on the MainThread with the Devmode FPS counter running. Although not as severe, they still prevent the simulator from running properly. This leads me to believe the issue lies within the main executable of flight simulator in these last two updates.

2023-08-26 04_37_49-Microsoft Flight Simulator - 1.34.12.0
2023-08-26 04_37_49-Microsoft Flight Simulator - 1.34.12.01474×800 85.9 KB

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6

Thanks for taking my suggestion in the spirit it was intended. It’s hard to be given advice which sounds like it’s blaming your system :slight_smile:

Your new testing makes it even more perplexing and difficult to understand what is different between our systems! They are similar spec and settings (even more so with you trying out vsync) but you see the issue and I don’t. The glaring difference of course is the cpu architecture. Not just in manufacturer AMD v intel but your system has the 3D vcache. I can’t remember if you posted in your OP that you’d tried to disable this (again temporarily as a test)?

7

*you are also using the same build of windows 11 as me. I’m on nvidia 536.23 BTW…

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My Nvidia Drivers are 537.13, released today. This was present on the last version as well.

The initial testing in the original post, the V-Cache was enabled.

For this last series of tests I disabled the 3D V-Cache. With the V-Cache off the latency spikes were not as severe, but they were still present.

I have since re-enabled the V-Cache (it can be switched off and off by changing power management modes in the Windows Control Panel) and have been watching flighsimulator.exe in the system resource monitor. Under typical load flightsimulator.exe averages about 17% CPU utilization. With every latency spike that utilization drops to under 3% for a spilt second.

I’ll have to do some more digging around and see if this is present with Windows started in safe mode.

1 Like
9

Couple of obvious questions I don’t think have been covered…

1 what is your TLOD/OLOD? Mine is 200/200. Oops just realised you’ve tried this at LOW preset.
2 is the phenomenon location dependent?
3 what wattage is your PSU?

Given your thorough testing methodology I’m guessing you’ve covered these. But just in case…

Also if you’ve any settings you’d like me to try changing please ask.

Edit: ignore these questions ~ you’ve done an A/B comparison which would eliminate them as potential causes!

10

I found on mine that DX12 was really unstable.

My Rig

Processor Intel(R) Core™ i7-9700K CPU @ 3.60GHz 3.60 GHz
Installed RAM 32.0 GB
System type 64-bit operating system, x64-based processor
SanDisk SSD G5

Edition Windows 11 Pro
Version 22H2
Installed on ‎10/‎28/‎2022
OS build 22621.2070
Experience Windows Feature Experience Pack 1000.22634.1000.0

NVIDIA GeForce RTX 4070ti with 12g memory
Driver 545.37/536.40
DisplayPort
G Sync Monitor: Dell 27 Gaming Monitor - S2721DGF
HP Reverb G2

Honeycomb Alpha & Bravo
Thrustmaster TPR Pedals

Internet Speed
230.9 Mbps download
32.5 Mbps upload

11

There’s no point in wasting time fiddling with every possible setting. The whole point of the beta performance evaluation is to keep the same settings of the current version and compare apples to apples.
Many people reported the performance degradation, please vote this thread and let’s cross fingers for the final SU13 version:

1 Like
12

I have similar short latency spikes as well with SU13 - RTX4090, everything on HIGH, DX11, I7- 13700

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The point of ‘fiddling’ with the settings was a targeted approach to try and isolate why the OP was seeing stutter on his system in this beta while my system with similar spec and settings wasn’t. Identifying the cause in this manner and feeding this info directly to asobo is surely the purpose of a beta rather than just saying ‘it’s broken’?

I don’t see any performance degradation in this beta so it’s not a straightforward regression.

2 Likes
14

Guys, I have had the very same issues Stuttering to the point i initially had Limited by main thread and manipulators throttling back to 1FPS with a 1500ms delay lol---- turn off Vsync - Set Nvidia Setting Shader Cache to unlimted. Turn off Threaded Optimisation…

In the MSFS i have disabled Rolling Cache and Deleted. Clear your Nvidia Cache folders DXCache/GLCache and DX Cache via the Disk Clean up tool.

Also i noted that clearing control profiles back to default and set audio to specific devices rather than default - these last two are anomalous…

You wouldnt believe what i went through to resolve yesterday 12 hrs non stop …
I also reinstalled Nvid Drivers and DDU to clean out then reinstalled… Check Flash drive perfomance etc the list goes on …

Seriously its been a learning curve but i am now on Dx12 and stable… with 47 FPS and happy again…Fortunately i did not have to remove any content or reinstall from scratch. I am also VR… so had the extra overhead of thinking i had issues with WMR +Toolkit etc … So my focus - filtered down through hours of troubleshooting and deduction is defo on the caching DXShaders and MSFS caching… but there were some anomalies around Sound settings devices and my Control profiles for throttle and joystick _ go figure on that — set back to default for all control devices and specifically selected the appropriate Sound devices NOT the defaults…

My problems initially started when conducted training scenarious as soon as i logged into cockpit then all went south… performance lag and unworkable…

My aim was to resolve with out uninstalling - which i couldnt stomach… fortunately i have not had to… NOTE i am now on DX12 also not DX11 anymore for the PC setup which i know affects VR also…

I run 3090 with I9 12k - 64GB ram - so knew it wasnt a performance issue per se…

Settings

08 October 2022
21:56

1. Hardware - RTX 3090 / Intel i9 12900k / HP Reverb G2 / 64Gb Ram / SSD 1 TB
2. MSFS VR Experience 
	a. 100% Render Scale (3180 x3100 per eye)
	b. Most MSFS Settings High or Ultra
	c. Volumetric Clouds High
	d. (Mostly Consistent 30Fps w/ motion repro in urban areas with High Cloud Settings
3. CPU
	a. Intel Extreme Tuning
	b. UnderVolt (Reduce Power)
	c. Overclock (Increase Performance)
	d. Increase Fan Speed using BIOS to reduce thermal throttling
4. GPU 
	a. GPU Tweak III
	b. Undervolt (Reduce Power)
	c. Overclocke (increase performance)
	d. Increase fan curves using custom curves
5. Nvidia Control Panel NCP
	a. Driver Version (Aug 23)
	b. Settings as per Captured Below
6. OpenXR Developer Tools
	a. Render Scale 100%
	b. Laters Runtime
	c. Motion Repro as required
7. OpenXR Toolkit
	a. As per below
	b. Final Settings for Nick
		i. Custom Render (4300x4200)
		ii. DLSS Perf
		iii. MR OFF
		iv. FPS ~47%
		v. Shaking Reduction -20% (Do Not Use with MR ON)
		vi. FoV as per below
		vii. FFR (Fixed Foveated Rendering) Eye piece?
		viii. MR (Nick prefers not to use with DLSS due to watering and improved clarity)
8. MSFS Settings
	a. As Listed below
	b. Ensure PC settings are setup as well (Texture Resolution PC needs to be Ultra)
	c. Ensure Monitor not brightest thing in room / MSFS window is small on desktop
	d. DX 11/12 Affects VR as well.
9. Every Flights and Levers
	a. Pre Load - Reset WMR Environment Data - Keep Head Still 5 Sec (Mitigate Stutters) / Clear Shader Cache
	b. On the Fly - Adjusting Custom Render Scale in OpenXR Toolkit
	c. If Stuttering : On the Fly - Volumetric Cloud Settings (Free to change as you go) High/Medium 20% Change / Clear Caches both folders and dx shader from the windows disk clean up tool.

image
image1122×804 54.3 KB

Note Shader Cache Size is now set to unlimited NOT driver default for all games… Global… as Default only allocates 1GB - If you want to specifically adjust MSFS you have to use Nvidia Profile Inspector to adjust for MSFS as settings not avail in Program settings…

image
image1080×846 36.2 KB

Had to break out screen shots - apologies

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image1102×404 32.4 KB

I have deleted my rolling Cache as shown above and — turned off and deleted— defo a caching problem in the past and present for me when the stutturing starts…

Also recommended using Dev Mode - with FPS enabled in MSFS (not to suck eggs) as i did glean some pointers for being limited by manipulators which mentioned VSync Pointer…very briefly.

4 Likes
15

Just to jump in here to report the same issue as seen in the OPs video.

Meanwhile I reinstalled the sim, latest NVIDIA driver etc.
I’m 100% sure that this issue is SU13 related as my sim haven’t had this issue before.

12700K, RTX 3080

2 Likes
16

Does anyone with these stutters use wireless keyboards or mice? I started getting random long pauses after SU12 and it was my wireless keyboard causing it - don’t know why and I tried a windows and game re-install but to no avail. Went wired and all problems went away. I have very similar specs to some of the users seeing these stutters and SU13B is super smooth for me.

1 Like
17

have you tried deleting the rolling cache?

I’ve found sometimes switching settings from what they are, applying, then switching back helps also. Things like LOD, OLOD, Tree and bush quality…

18

Oddly enough I am running a wireless mouse and keyboard. Plugging them both in did reduce the latency stutters a bit, but they are still there and still pose an issue.

For the time being I will rollback to Sim Update 12, at least until the next SU13 beta. Hopefully the next beta release will eliminate the issue, fingers crossed.

1 Like
19

No, I don’t have

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FYI @CarbonSpark9321
Gaming rig stutter-free.

  • Be quiet silent base 802
  • MSI MAG Z790 Tomahawk WIFI
    BIOS - H70
    HT - enabled
    Virtualization - disabled
    Re-size bar - enabled
  • PSU MSI MEG Ai1300P
  • i9 13900K
  • NZXT Kraken Z73
  • 32GB Ram DDR5 7200MHz 2x16GB
  • LG 27GL850-B
  • Gigabyte RTX 4090 Gaming OC // latest driver // G-Sync enabled
  • Sound Blaster AE-9
  • 4xNVMe // 2TB for msfs
  • 1xSSD
  • 1xHDD
  • Logitech X56 H.O.T.A.S
  • VKB Gladiator NXT Evo Space Combat Edition
  • Thrustmaster T300 RS racing wheel
  • W10 pro latest ver without KB5029331

Cache,cache,cache …

Clearing the cache can be beneficial for a couple of reasons:

  1. Data Consistency: MSFS uses a cache to store various types of data, including scenery, textures, and other assets. When an update is released, it might involve changes to these assets. If the cache is not cleared, you might encounter inconsistencies between the old cached data and the updated data, leading to graphical glitches, missing textures, or other issues.
  2. Performance Optimization: Over time, cached data can accumulate and take up significant storage space. Clearing the cache before updating ensures that you start with a clean slate, potentially improving the game’s performance by preventing it from accessing outdated or unnecessary data.
  3. Bug Prevention: Occasionally, updates can introduce new bugs or conflicts with existing data. Clearing the cache can help prevent issues arising from outdated cached data conflicting with the updated game files.

Before clearing the cache, make sure to understand that this action will remove cached data, and the game might take longer to load certain assets the first time you play after clearing the cache. However, this initial loading delay should be temporary, and subsequent gameplay should benefit from having a clean cache.
Always ensure you have a backup of any important saved flights or settings before performing any major changes.

  • Clearing the driver and directx cache might be recommended in certain situations, although it’s not a common practice and should be approached with caution. Driver caches, often associated with graphics drivers, store information about previously used resources and configurations. Here are a few reasons why someone might consider clearing the driver cache:
  1. Driver Update Compatibility: Sometimes, a new version of MSFS might require specific updates or optimizations in your graphics driver to work smoothly. Clearing the driver cache can help ensure that any new configurations or settings related to the game are properly utilized by the updated driver.
  2. Performance and Stability: Clearing the driver cache can help reset any potential conflicts or corruption that might have occurred in the cached data over time. This could lead to improved performance and stability, especially if the cached data was causing graphical glitches or crashes.
  3. Resolving Issues: If you’ve been experiencing issues with MSFS, such as graphical anomalies, crashes, or performance drops, clearing the driver cache might be a step to troubleshoot and potentially resolve those issues.

However, it’s important to note that clearing the driver cache carries some potential risks and drawbacks:

  • Loss of Custom Settings: Clearing the driver cache could reset any custom settings or configurations you’ve made for your graphics card, which might result in having to reconfigure them after clearing the cache.
  • Temporary Performance Impact: After clearing the driver cache, your graphics card might take a bit longer to load and process shaders and other resources the first time you launch Flight Simulator. This could lead to slightly longer loading times or reduced performance initially.
  • No Guaranteed Improvement: Clearing the driver cache might not necessarily lead to noticeable improvements in all cases. If your graphics driver is already up-to-date and functioning well, clearing the cache might not provide significant benefits.

Delete these folders/files:

%localappdata%\D3DSCache
%localappdata%\NVIDIA\DXCache
%localappdata%\NVIDIA\GLCache
%appdata%\NVIDIA\ComputeCache

Important!

1 Start your PC in safe mode

  • Click start
    1start
  • Click power icon
    image
  • Press and hold left SHIFT key and click restart
    image
  • Select Troubleshoot > advanced options > startup settings > restart
  • Select 4 - Enable safe mode

2 Click start and type

%localappdata%\D3DSCache

Press Enter
Delete all folders

3 Click start and type

%localappdata%\Nvidia\dxcache

Press enter
Delete all files

4 Type

%localappdata%\Nvidia\GLCache

Press enter
Delete all folders

5 type

%appdata%\NVIDIA*ComputeCache*

Press enter
Delete all folders

Restart PC.

Flush outdated data - delete .dat files.

How to
  1. Click start and type

%appdata%\Microsoft Flight Simulator\SceneryIndexes

Delete every file in this folder.

Also delete and turn off rolling cache via MSFS settings.

For testing purpose uninstall GPU drivers via DDU.
https://www.wagnardsoft.com/content/DDU-Guide-Tutorial
Install GPU driver without geforce experience and Nvidia HD Audio.

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