Ideas on how to troubleshoot recurrent hard pauses?

[RJC68 823]

On 10/14/2022 at 4:25 PM, Noel said:

Rich, next time up if if works out for you, in something demanding like PMDG/Fenix, can you run DevMode and observe over at least 20 minutes if you ever see these sudden drops below 30FPS as shown in my images?  You would need to lock frame by Vsync to 30 to try to duplicate my system.  Your CPU is more potent but what's happening here happens when there is ample CPU and GPU headroom, so appears to be about a larger disk read in flightsimulator.exe.  Certainly the DiskBench I did suggests the NVMe is not hard on the CPU at all.  Since I've lost the previously pause-free simulator I'm tempted to go ahead and install Win 11 on top of this fresh Win 10.  I have a hard time believing this will help, but I don't know where else to go now.  We really don't know if separating OS and MSFS is required and perhaps this experiment might show something.   If you can run at 40FPS locked that might be closer since your CPU is a good 25% faster for main thread processing over mine.

Hi Noel,

Sorry for the late reply. I got around to do some flying last night in the Fenix (Lots of yard work to go here this time of year lol) and did as you asked, with frames locked to 30 and VSYNC on I did not see any pauses or stutters and the graph in developer mode stayed consistent. 

How are you managing locking your frames? Are you using the in sim option ? I did lots of testing when I built my PC and I found the best was the following combination. Turn VSYNC On in NVCP and then use Riva Tuner to lock my fps. I always used to use the in sim option but after SU8 I was finding even though I had locked my fps they were jumping around. I must admit I have not tried in sim for a while as the method I described works really well.

Really hoping you get to the bottom of this.

[Jack_Sawyer 4,600]

2 hours ago, Republic3D said:

Does this stutter happen when playing other games? Simulation type or anything that needs stable and smooth fps?

Yes sir, 1/3 of a second at stopwatch precise 60 second intervals.  I played Skyrim at 60 FPS on Steam and smooth as glass and not one stutter no matter how hard I pushed it.

[Noel 4,486]

33 minutes ago, RJC68 said:

Hi Noel,

Sorry for the late reply. I got around to do some flying last night in the Fenix (Lots of yard work to go here this time of year lol) and did as you asked, with frames locked to 30 and VSYNC on I did not see any pauses or stutters and the graph in developer mode stayed consistent. 

How are you managing locking your frames? Are you using the in sim option ? I did lots of testing when I built my PC and I found the best was the following combination. Turn VSYNC On in NVCP and then use Riva Tuner to lock my fps. I always used to use the in sim option but after SU8 I was finding even though I had locked my fps they were jumping around. I must admit I have not tried in sim for a while as the method I described works really well.

Really hoping you get to the bottom of this.

Thanks Rich yes I've used the in-sim option of vsync with the 50% divider of 60Hz or 30FPS.  I've used RTSS several times in the past and also NVCP and found in sim version to be the best.  Might be worth a try again w/ RTSS.  

I just now after reading your note re-tried RTSS.  Frames aren't jumping around using in-sim but the DevMode OSD graphs looks far more stable FWIW and that perhaps should equate to smoother total performance so great we'll take it!

I've done many seeming little things to see if they made a diff and I'm not sure which one it was at this point but it *seems* like the spikes are gone now.  It may well have been turning off desktop theme and slideshow which was set to change picture every....1 minute!   It's a little bit early to tell but the issue may be gone.  Last night flying into KOAK I saw none of them, and today about to land in Nice FR I'm not seeing them, except for rare ones that are related to clicking on something in-sim (like bringing up the DevMode console) but again the every 55 sec or 60 sec issues seems to have resolved!

[RJC68 823]

28 minutes ago, Noel said:

Thanks Rich yes I've used the in-sim option of vsync with the 50% divider of 60Hz or 30FPS.  I've used RTSS several times in the past and also NVCP and found in sim version to be the best.  Might be worth a try again w/ RTSS.  

I just now after reading your note re-tried RTSS.  Frames aren't jumping around using in-sim but the DevMode OSD graphs looks far more stable FWIW and that perhaps should equate to smoother total performance so great we'll take it!

I've done many seeming little things to see if they made a diff and I'm not sure which one it was at this point but it *seems* like the spikes are gone now.  It may well have been turning off desktop theme and slideshow which was set to change picture every....1 minute!   It's a little bit early to tell but the issue may be gone.  Last night flying into KOAK I saw none of them, and today about to land in Nice FR I'm not seeing them, except for rare ones that are related to clicking on something in-sim (like bringing up the DevMode console) but again the every 55 sec or 60 sec issues seems to have resolved!

That's great news Noel,

If you are using Riva pull up the onscreen information and add the frametime graph it will show you how consistent your frame timing actually is. There are some other good stats you can add as well for monitoring and troubleshooting issues. I have it bound to a key combination that I can turn it on and off from my Stream Deck.

One thing I found really important when I was locking to 30fps was always making sure I stayed GPU limited. I could max out every setting and at 30fps GPU usage was pretty low (I had a 3080TI as well) What I ended up doing was pushing the render scale up to 130 to try and keep the GPU timing in the dev mode screen to just under 30ms matching your frame time. This gave me GPU usage of around 80% still leaving some headroom.  You can lower the main thread timing by adjusting the TLOD & traffic. I found the sweet spot for the Main thread was around 18ms and GPU around 28ms. If you do this your frame time graph will be a smooth solid line and you should be stutter free

Have a look at the part of this thread I bookmarked, it explains how to adjust the Main thread & GPU timing

https://forums.flightsimulator.com/t/stutters-on-final-lower-end-systems/474357/68

Edited October 17, 2022 by RJC68

[Noel 4,486]

35 minutes ago, RJC68 said:

That's great news Noel,

If you are using Riva pull up the onscreen information and add the frametime graph it will show you how consistent your frame timing actually is. There are some other good stats you can add as well for monitoring and troubleshooting issues. I have it bound to a key combination that I can turn it on and off from my Stream Deck.

One thing I found really important when I was locking to 30fps was always making sure I stayed GPU limited. I could max out every setting and at 30fps GPU usage was pretty low (I had a 3080TI as well) What I ended up doing was pushing the render scale up to 130 to try and keep the GPU timing in the dev mode screen to just under 30ms matching your frame time. This gave me GPU usage of around 80% still leaving some headroom.  You can lower the main thread timing by adjusting the TLOD & traffic. I found the sweet spot for the Main thread was around 18ms and GPU around 28ms. If you do this your frame time graph will be a smooth solid line and you should be stutter free

Have a look at the part of this thread I bookmarked, it explains how to adjust the Main thread & GPU timing

https://forums.flightsimulator.com/t/stutters-on-final-lower-end-systems/474357/68

I adjust TLOD to insure at touchdown MT is not more than about 22ms or so.  Obvious 18 is better but I still have smooth perf via in-sim vsync to 30 if I'm not more than about 22-23ms.  At arrival it's always more demanding than at departure even in the same airport, so what I often do is set TLOD somewhere such that the MT is around 18 or 19ms because upon arrival I've learned it will usually be 22-23ms depending on the airport, but in general I believe there is an accrued debt that evolves over time such that at arrival it will always be greater than at departure given similar/same airport.

Here's a video of what the graphs look like now, and this is a full 1m20s and you won't see the big pauses.  This is a pretty light airport, LFMN, and as we got to touchdown it got a little stuttery even though MT was only around 22ms.  This was in DX11.  Last eve was into KOAK a much more complex landing and had absolutely no hint of a stutter from TD to gate, and no pauses.   That was using in-sim vsync, but DX12.  So next will try DX12 w/ RTSS and see how she goes.   I did note GPU was running quite low, around 15ms or so which is much lower than when using in-sim vsync.  Also, this time I did not use scanline x/2 in RTSS, but just their straight framerate limit.  Be sure to select 1080p for this video else it may be hard to see the graph!

 

Edited October 17, 2022 by Noel

[Maxis 1,857]

Glad to see youre actually taking the time to eval the differences in the limiters. 

Hopefully you have gone through your startup apps and background apps and gone through them with a very critical eye.

[Noel 4,486]

8 minutes ago, Maxis said:

Glad to see youre actually taking the time to eval the differences in the limiters. 

Hopefully you have gone through your startup apps and background apps and gone through them with a very critical eye.

I've actually taken the time to evaluate limiters many times previously back pre and post MSFS but it's changed and is worth another look, at least I think so.  As mentioned, flew into KOAK in the 738 last night w/ no hitches whatsoever and that was w/ in-sim vsync.  I'm not sure how well the Dev Mode frametime or whatever the upper yellow bar indicates correlates w/ smooth flight because once again as I mentioned flying into rather benign LFMN I had some stuttering that I don't normally have when there is ample MT headroom, so not sure what to think.  There was a period back in the FSX/P3D days where I disabled noncritical processes and services from running but have gotten away from that as I really had no problems maintaining smooth flight for most of MSFS' history, but recently things changed.   I look forward to try DX12 now w/ RTSS and see what happens.  The yellow bar in DevMode looked way worse as I landed at KOAK, yet there were no stutters.  There is only one thing I can say for sure:  it's hard to draw any conclusions on any of this 🤔