Latency and Stutters on SU13 Beta

I have a very similar configuration (monitor, PC, etc.) and I have EXACTLY the same symptoms. Fully concur.

I wish Asobo would delay the SU13 release If the performance degradation issue is not resolved.

There’s no point on having system update, but with less and less performance.

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I can officially report there is NO change in the latency stutters with the beta update that released today. They are still there even after a complete fresh reinstall of Microsoft Flight Simulator.

Not a good sign. :unamused:

Edit: Post has been moved from General Beta Discussion to Install, Performance & Graphics.

Edit 2: This has been officially logged with Asobo as a bug!

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Glad its logged. Now lets see how they go about fixing it.

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After reading some of the performance posts I remembered one thing. Could you guys check if you have shaders cache disabled or set to a very small size at Nvidia control panel (I´m not sure if AMD has a similar setting)? The shaders cache on hard disk improves both performance and game loading times, so shader cache should not be deleted too frequently unless you are using multiple games at a time that compile a lot of shaders or you already uninstalled some games so those shaders are not needed anymore. If you are using MSFS frequently then storing shaders makes real sense.

The two main reasons to use a shaders cache, specially in the case of games with detailed graphics and heavy textures like this one, are the following:

  • Prevents game from having to regenerate shaders during loading everytime if there´s no room enough to store them. Shaders generation happens once game is launched for the first time or upon a new game patch that modifies shaders. If cache is too small then they need to be generated again everytime you lauch game as older files will be replaced by new ones due to limited room available in the cache or in case it´s disabled.

  • Allows GPU to load them directly from disk to VRAM if they are already existing, using the stored pre-compiled files from previous game sessions. In that case GPU would just create on demand the new ones which were not existing before.

I have the feeling that game was loading shaders during flight loading before the AAU2 patch and now it loads them dynamically (upon demand). Unreal Engine has a config variable that allows to load all shaders upon start as well and that indeed solves many similar issues in graphically intense games like the ones we are facing now in AAU2 and SU13 beta (camera freezing while panning and excessive HW workload on dense scenarios). The only benefit of not loading shaders upon start is a lower memory usage so that may explain why Asobo was tempted to use this approach now in the never ending battle to squeeze Xbox beyond its limits.

This is not going to fix the sttuters and freezes because they are caused by main thread overloading in my opinion (which is a different animal) but could prevent to make things even worse until final SU13 is released.

Cheers

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So far, Sim Update 13 Beta 1.34.14.0 seems to have solved about 99% of the latency induced stutters that I was seeing on the last four builds. MainThread response time is a little high, holding at 15-16ms in the yellow, but as of right now, the Sim Update 13 Beta is in a usable state.

More to follow.

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Just loaded up the.14 beta after having left the.11 beta, which was terrible with stutters.

Initial impressions are good with the latest .14 beta but I noticed something interesting with respect to stutters and focus on the sim (as opposed to clicking/focusing on another app like Task Manager or more interestingly, Air Manager).

Test setup/scenario:
5800x3d, 4090 driving 3x55” TVs @4k, 32GB 3600 memory, second graphics card Intel A380 driving 4x touchscreens for Air Manager, DX12, DLSS 2, DLSS3 frame generation, FSLTL, FSUIPC, Air Manager , mostly ultra settings, etc… in other words, fairly high end system running a heavy load with lots of ancillary stuff going on too.

In the PMDG 737-700 with weather partly cloudy over the Sea of Cortez at FL350 between MMSD and MMPR, both of which are freeware airports from FlightSim.to.

Three interesting outcomes:

  1. With the sim in focus (i.e. mouse clicked in the main view of the sim) the framerate is really smooth ( both by subjective “feel” and also by looking at the dev mode FPS display). For the given scenario, it was 36-38FPS with very little “hair” noise on the frame time graph. Flickering between limited by main thread and limited by GPU. The center main sim view has its FPS “doubled “ due to frame generation. It’s noticeably smoother than the side screens. This is status quo, and not much different than the previous SU12 performance I experienced.

  2. Now, if I touch any of my Air Manager panels (to turn on wing lights, for instance), the frame rate GOES UP to 45-47FPS (that’s a ~25% increase in FPS, by the way!!!). The first kicker is that the terrible stutters are back. And the frame rate graph is much more “hairy” with noise. But the average frame rate is measurably and noticeably better. The second kicker is that the DLSS 3 frame generation is gone from the center screen (as it always has been when the sim isn’t In focus). If I click back on the main sim screen, we go right back to the lower frame rate scenario described in number one above.

  3. Just for kicks, I tried another app in focus. This time it’s Windows Task Manager. I had it covering about 30% of the 4K TV with the full screen left view of the sim underneath the Task Manager window. The frame rate again shot back up to 45-47FPS but this time, the stutters were much, much less frequent and severe. Back and forth main sim window to Task Manager and back, the frame rates were repeatable as described above. Then I thought, well maybe the sim doesn’t have to render all of those pixels under the Task Manager window so maybe that’s why I’m seeing the FPS increase. I then moved the Task Manager window off of the TV and onto one of my smaller touchscreens and did the same back and forth test. Lo and behold, the FPS increase was the same with the Task Manager window in focus. So I had an almost perfect scenario, except that the frame generation isn’t working on the main center sim TV.

So what does this all mean and what am I getting at, you might ask? I’m not quite sure, to be honest.

I’m seeing strange behavior in sim performance that doesn’t totally make sense. It seems like the sim has a new behavior related to being in focus or not. It’s plausible that it’s related to the changes made to fix the white dot and white frame issue. Those also seem related to focus.

Anyway, those are my observations and I figured I’d try to write them out in hopes that it might shed some light on the latency and stuttering issues we’ve been seeing in the new beta.

I’ll probably do some more testing and try to formalize my findings, if I can find the time.

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The latest build (1.34.14.0) solved the stutter problem that was happening on previous builds on my pc

these stutters just started happening for me on this new build :frowning:

Ryzen 7 5800X
3060ti
32gb DDR4 @ 3200mhz

Didn’t really pick up until after i took off from Rome this morning. preflight on the ground was smooth as butter.

Out of curiosity, when it started stuttering, did you happen to click on another application? I wrote up my findings on the other choppy/stuttering graphics thread regarding sim focus.

EDIT: OOPS, I guess I posted my findings above, in this thread. FWIW, I think the Choppy/Stuttering graphics thread and this one should be merged. They are effectively addressing the same issue.

no significant changes. occasional switching between screens to check charts or whatever. Usual suite of apps navigraph and smartcars. only other thing was browser with about 4 tabs but that has not affected things in the past.

I know what you’re talking about though but I haven’t noticed any stuttering relating to the window focus. occasionally i will but it clears right up when i click back onto the game.

I did a search around for Limited by Coherent GTUI Thread issues as that is what i was finding in the dev mode FPS counter. Couldn’t find much but seems some people had the issue solved with .14 magically. Even turned down some graphics settings

I think someone said it earlier there’s a bug in the .exe. I’m gonna update drivers and do the needful and try again later today (when my new throttle hopefully shows up)

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Take a look at my reply to other post: Reducing MSFS **CPU** load (Limited by CPU) - #29 by geloxo

MSFS needs to be in focus (mouse click or Alt-TAB). If not the FPS readings are giving the ones from Windows desktop. Performance is also impacted as when MSFS is not in focus you may potentially get more stutters (for instance G-sync produces a worse output). Unfortunatelly when you see those FPS increases when going to your Air Manager panels they are not real. That´s because you are getting Windows desktop in focus instead of game, as you are interacting with Air Manager panel app not with MSFS main screen.

I posted a trick below that post. You can change your mouse pointer color to know when you are at desktop or at game. Some things are still allowed: using mouse wheel on another window (so doing zoom at Littlenavmap app for instance) will not take game´s focus to give it to that window, but any mouse click will do it.

I think most people is not even aware of this issue and they may be getting worse results than they should in some situations. Or even the oppossite, thinking that game performs better than it really does, when that´s just a placebo because it´s desktop de one giving such good results. As you see the solution is really simple but you need to remember it: always click once anywhere on MSFS main screen after you finished using other screens or apps.

Cheers

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I read through your other post and to some extent I agree but I don’t see the frame rate going up to the 120FPS of my 120Hz monitors. Rather, I see something moving around like 45-47FPS in my example from my post. The sim definitely wants to be (and should be) in focus for best performance. It is definitely smoother with the sim in focus. I’ll have another look at sim focus with what you’ve said in mind.

I like your trick of changing the mouse icon/color for Windows. I’ll definitely do that. :+1:

Regarding always getting in the habit of clicking back in the main sim screen after diverting focus, yeah, I’m definitely in the habit. In fact, I have created a macro button on my Stream Deck that does exactly that. It virtually clicks in the main window, actually twice because sometimes the first click doesn’t seem to work. It’s using an addon from BarRaider Mouse Commands · BarRaider/streamdeck-supermacro Wiki · GitHub Works like a charm!

In related news, Air Manager has a beta out (v4.2) that either maintains or reverts focus (not sure which) on the sim when interacting with the panels. It works great to address just this issue. Only problem is that in my experience, it’s causing other issues with the sim (CTD) and with the Knobster (too much latency). Once they get the bugs worked out, it will be a great new feature for use with the sim. I’m pretty deep down the rabbit hole of a home built sim cockpit with lots of screens and hardware. Air Manager is a crucial part of my sim experience and I can’t/won’t use the sim without it.

Similarly, @RoastGnu 's POPM has features that also revert focus to the sim after interacting with popped-out sim instrument windows. This is awesome as well!

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I use G-sync so maybe that´s the difference. Anyway if you see any FPS change then that´s enough for the test. V-sync may be trying to cap your FPS to 60. I haven´t used V-sync for years so honestly I don´t know if something changed with the current Windows versions or Nvidia drivers.

Cheers

I’m not using any limits for frame rate FWIW. I can’t get Gsync to work. I think my Display Port to HDMI adapters aren’t up to the task.

i’m having unprecedented amount of ctd’s like never before!
anyone else ?

You need to do the following to enable G-sync:

  • Enable G-sync in your monitor, in case it has an OSD menu with an option for that, as it could be disabled in default settings (the option should be under OSD config menu)
  • Enable G-sync for full screen mode at Nvidia panel (full screen + windowed mode option creates lag and fps loss when several windows overlap)
  • Enable also V-sync at Nvidia panel (yes, it´s also needed so put it in the global profile)
  • Disable V-sync in game

If your monitor has a way to display the current refresh rate (normally this could be at OSD menu) you can check it a couple of times to be sure the refresh rate is being changed to match the current FPS figures you have in game.

When G-sync works for one game it will work for any other. You just need to be sure that game runs in full screen mode. If you have problems with any game you can try to enable the G-sync full screen + windowed mode. It´s also fine to use it but it has that lag issue while several windows are displayed at the same time, but is vanished as soon as you just keep only one active and minimize the others.

Cheers

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I’ll try that. The one thing I hadn’t tried yet was the NNCP global Vsync.

Im still running v12 (not beta and never have) and this has been happing to me since the weekend, and no changes to my system…

Closed as fixed in Sim Update 13: Release Notes - Sim Update 13 [1.34.16.0] Available Now