P3Dv5.2HF1 Large Freeze/Stutter

[flynryan692]

Hello, I'm having a real head scratcher of an issue with P3D v5.2 (Client, Content, and Scenery are v5.2.22.27615) where when I am flying for long periods of time I end up developing a freeze/stutter issue where the sim will basically freeze for a second or more. As time goes on this issue get progressively worse. In some cases it will go away for a few hours before coming back. This is extremely similar to the issue P3Dv5 had with HTML menus when it first launched. I've tried to investigate multiple theories over the last month and I keep coming up short.

For starters, here are my system specs.
i9-9900KF overclocked 4.9Ghz
Gigabyte Aorus Pro Z390 MB
Nvidia RTX 3070Ti
32GB DDR4 3466Mhz
P3D v5.2 HF1 and all associated addons are installed solely onto a 500GB Samsung 860 evo SSD.
Windows 10 Pro

Addons being used at PMDG B747-8, PMDG NGXu, ASP3D v7877, chaseplane 1.2.54, ASCA v7884, FSRealTime, vPilot, Volanta, PFPX, FSUIPC v6.102 as well as ENVTEX and ENVSHADE, Navigraph simlink, GSX and SODE. P3D and all third party addons are ran as administrator.


Here is the issue, back in early September I was flying a long haul flight from KLAX to RKSI when a few hours out of RKSI my sim began to have a hard stutter/freeze problem. It developed into something that was happening every 30-60 seconds and then it would go away for a couple minutes and return. Initially I was frustrated but figured something weird was happening with my system and it was a one off. I did try closing out of Navigraph simlink and restarting it as this is a known issue with that software, and that has worked long ago when it caused this problem. That did not work this time.

It did the same thing the following day while flying RKSI-PANC, beginning after many hours of flying as the sun was rising. Now I thought something was wrong with an addon, not ruling out the B748 as I hadn't flown it in 6+ months, or my system. After the flight I uninstalled my graphics driver with DDU, cleared P3D cache, and reinstalled. I also doubled checked my AS/ASCA, ENVTEX and ENVSHADE settings and reinstalled those as well. Finally, at the end of the flight to PANC I closed all of my third party applications so I only had P3D running and the problem persisted. So I checked my Windows update and there was a security update (KB5005565) installed a few days prior so I uninstalled that update and paused Windows updates so it wouldn't reinstall. I then flew another flight a couple days later from PANC-KJFK, no stutters!

Well I thought I solved the problem there, either GPU drivers, or the Windows update. I went to fly a shorter flight still in the PMDG B748 from KJFK-KORD and while taxiing I accidentally opened the ATC menu which caused the consistent stutter from the early days of P3D v5 with HTML menus. I do have the "fixed" version, so it was odd it did that, but I couldn't even taxi so I quit the flight. I redid it later that day without issue, but I also went and disabled the HTML ATC menu (my main menu is the Simconnect menu and I do not display text like 'brakes' 'parking brakes' etc on screen ever).

I then flew KORD-PHNL still in the B748 and the problem once again propped up after roughly 2hrs of flight. Although I have P3D and all addons excluded in Windows Defender, I decided to try turning off real time protection just to see. A few minutes later the problem was gone. Several hours later as I got closer to HNL the problem came back, so I went to check if Windows turned real time protection back on and it did. I tried to turn it off again but the problem persisted. After that flight I decided to replace Windows Defender real time protection with Bitdefender, and I made sure to exclude all of my flight simming stuff.

A couple days later I flew PHNL-YSSY and it had no issues for most of the flight until I got to New Caledonia as the sun had just rose, and the problem came back. So it wasn't Defender or real time protection (I kept Bitdefender anyway, great program). I've looked around for solutions and nothing is clicking here. I then flew YSSY-VTBS and that flight went great, until the sun rose near the end of the flight and the problem came back.

I was starting to think maybe this was isolated to the PMDG B748 as this problem was only occurring since I started flying it. It was not happening with the B744, NGXu, or anything else. Last night I installed the new Nvidia 496.13 drivers, not really holding my breath that would fix it but figured it was worth a shot. I also installed ISLC to clear standby memory, not that it's really an issue for me with 32GB, but I am willing to try anything. So today I am flying short flights with the NGXu, I have been in the sim roughly 7 hours straight and the problem just came back. So it is not the B748 causing this, and the NGXu did not have the issue in late August but now has it.

I am at a loss at this point and am wondering if anybody has any other suggestions for solving this. It does seem to have to do with flying for long periods, with the except of the ORD-HNL flight where it popped up after a couple hours, it almost ALWAYS happens when I have been flying for 6-7 hours or more. I grabbed some screenshots from task manager showing my CPU and GPU both dipping when I get this large stutters. The highlighted part of the graph shows the stutter/freeze.

To summarize I have tried the following...

- Closed all third party addons
- Closed third party software running in background (NZXT CAM, Aorus software, etc)
- Disabled all HTML5 menus and text in P3D
- Uninstalled most recent Windows Update (KB5005565)
- Disabled Windows Defender Real Time Protection, excluded all addons from Defender, and replaced defender with Bitdefender
- Installed new GPU drivers (x2) using DDU, cleared shader cache, checked AS/ASCA/ENVTEX/ENVSHADE settings and resinstalled
- Run ISLC to clear standby memory when standby memory is greater than 1GB and free memory is less than 4GB (probably useless)
- Checked drive health for all of my SSD's
- Ensured all other drivers were updated

What I have not yet done
- Tried older GPU driver from August
- Flown long flights with addon aircraft not made by PMDG
- Cleared generated files, or the prepar3d.cfg
- Nuked my system and installed a fresh copy of W10 (or upgrade to W11)

I am probably missing some other step/thing I did, I've have been trying everything. This issue sort of came out of the blue so it's really hard to pin point the culprit.

[flynryan692]

Sorry, I put this in the wrong section on accident...

[Martyson]

@ flynryan692 ,

Were you running all this during the flights mentioned in this post?

"Addons being used at PMDG B747-8, PMDG NGXu, ASP3D v7877, chaseplane 1.2.54, ASCA v7884, FSRealTime, vPilot, Volanta, PFPX, FSUIPC v6.102 as well as ENVTEX and ENVSHADE, Navigraph simlink, GSX and SODE. P3D and all third party addons are ran as administrator."

Have you asked PMDG support?

Do you use P3D Time acceleration ?

Do you use PMDG's Time acceleration ?

Home built PC ?

Do you use a second PC or Tablet to show a moving map ?

PC filters and fans clean?

[flynryan692]

@ flynryan692 ,

Were you running all this during the flights mentioned in this post?

"Addons being used at PMDG B747-8, PMDG NGXu, ASP3D v7877, chaseplane 1.2.54, ASCA v7884, FSRealTime, vPilot, Volanta, PFPX, FSUIPC v6.102 as well as ENVTEX and ENVSHADE, Navigraph simlink, GSX and SODE. P3D and all third party addons are ran as administrator."

Have you asked PMDG support?

Do you use P3D Time acceleration ?

Do you use PMDG's Time acceleration ?

Home built PC ?

Do you use a second PC or Tablet to show a moving map ?

PC filters and fans clean?

Yes all of those addons were running or installed during the flights

Haven't asked PMDG yet as I haven't identified it as a PMDG only issue. I will do some flying with something that isn't PMDG to see if it still happens first. If it doesn't, it's PMDG and I will seek their assistance, if it does it is not being caused by PMDG.

No time acceleration of any kind

My PC is home built by me

I do have an iPad for charts, but I do not use it. I either use Jeppesen charts I use for work, or I use Navigraph charts through my web browser.

PC filters and fans are clean.

[JorgenSA]

Flyryan692,

The only thing from this list:

"What I have not yet done
- Tried older GPU driver from August
- Flown long flights with addon aircraft not made by PMDG
- Cleared generated files, or the prepar3d.cfg
- Nuked my system and installed a fresh copy of W10 (or upgrade to W11)"

that you should do, is the second item. Leave all the others alone, at least for now.

What you can do in addition to that item, is to check that no CPU-time consuming, or other resource-consuming tasks are running in the background. I am thinking of Cortana and iTunes just to name a couple of possible culprits here, there could be many others.

Also, you should update your FSUIPC, the current version is 6.1.5. If you are using the registered version, then start P3D, select any flight and then on the menu bar, when it appears, go under Add-ons and FSUIPC and turn off its automatic backup option.

Jorgen

[Martyson]

@ flynryan692 ,

Were you running all this during the flights mentioned in this post?

"Addons being used at PMDG B747-8, PMDG NGXu, ASP3D v7877, chaseplane 1.2.54, ASCA v7884, FSRealTime, vPilot, Volanta, PFPX, FSUIPC v6.102 as well as ENVTEX and ENVSHADE, Navigraph simlink, GSX and SODE. P3D and all third party addons are ran as administrator."

Have you asked PMDG support?

Do you use P3D Time acceleration ?

Do you use PMDG's Time acceleration ?

Home built PC ?

Do you use a second PC or Tablet to show a moving map ?

PC filters and fans clean?

Yes all of those addons were running or installed during the flights

Haven't asked PMDG yet as I haven't identified it as a PMDG only issue. I will do some flying with something that isn't PMDG to see if it still happens first. If it doesn't, it's PMDG and I will seek their assistance, if it does it is not being caused by PMDG.

No time acceleration of any kind

My PC is home built by me

I do have an iPad for charts, but I do not use it. I either use Jeppesen charts I use for work, or I use Navigraph charts through my web browser.

PC filters and fans are clean.

@ flynryan692 ,
You mentioned:
"Haven't asked PMDG yet as I haven't identified it as a PMDG only issue. I will do some flying with something that isn't PMDG to see if it still happens first. If it doesn't, it's PMDG and I will seek their assistance, if it does it is not being caused by PMDG."

Good initial plan.
Let me know the results of the test.

[flynryan692]

A little update, I did a test with another addon and didn't have the problem. Before I run off to PMDG, I am testing one thing. I ran a SimConnect console while flying a PMDG product and notice they run a lot of stuff constantly through SimConnect. There is an old FSX bug that apparently is still causing some issues in P3D to this day where SimConnect has too many connections and starts dropping things, which then reconnect, which causes a stutter. Sure enough in the SimConnect console I could see all of the PMDG connections not send any data (or rather, SimConnect not receive any data from PMDG?) when I got a stutter. I've got it set so that SimConnect will accept 255 connections instead of the default 64 through a local Pipe connection. I am going to see if that resolves it and if not I think I have done enough to start asking PMDG for help.

[flynryan692]

I got nowhere with SimConnect, however I did a fresh install with Windows 11 and only installed the NGXu and two sceneries, plus a few other things like ASP3D. The issue has come up again.

I have noticed that when the stutter happens the GPU sees a 100% spike in Copy, you can see it in the screenshots I linked in the OP. Further research tells me that it could be hot VRAM, which with a factory overclocked 3070Ti, in a small H500i case, this makes sense. The issues didn't come up until early September, which is when I moved to the 471.96 drivers, which makes me wonder if something was introduced starting with that driver. I'll have to make sure the older drivers will work in Windows 11 before trying them, but in the meantime I'm going to try and under volt my GPU a little and add a more aggressive fan curve to see if it helps.

[AjSkyMan]

Quick aside to start, would it be possible to have a moderator or admin move this thread to "Prepar3D Client Application Questions"? I feel we may get more eyes there.

Okay let's dive in...

@flynryan692 I am happy to say you are not alone. After literally months of troubleshooting and Googling, I came across your post. The bad news is that I don't have a solution for you, but I'm hoping we can find a few more folks with this same issue and come to some sort of a conclusion with the help of the community.

I'll try to follow a similar format from your original post.

To start, a description of my problem. After several hours of flight, my sim begins to freeze/stutter. It starts out with freezes lasting a second or two, and gets progressively worse with time. If the sim is left to run for another 15-20 minutes, it will eventually devolve into being frozen for 20-30 seconds, and unfrozen for 2 or 3. The sim will even occasionally go "not responding" according to Windows, complete with greyed-out application window and spinny wheel 'o death. What is interesting though, is that it ALWAYS comes back and never CTDs. I can let it run in this constantly frozen and unfrozen state for hours and it never CTDs. This is the only application on my PC that behaves this way, and when P3D is having fits, the rest of the PC is completely usable. I went so far as to launch another game today while P3D was freezing, which ran with no issues, locked at 60 FPS.

My system specs:
- AMD Ryzen 9 5900x
- MSI MAG X570 Tomahawk Wifi
- NVIDIA GeForce RTX 3090 Founders Edition
- 2x G.Skill F4-3600C16-16GTZN (32GB total @ 3600MHz)
- C: Samsung 970 Evo Plus 2TB <- windows installed here
- D: Samsung 870 Evo 1TB <- this is where P3D and all addons live
- Corsair RM1000x PSU
- Windows 10 Pro 21H1 19043.1348
- Prepar3d v5.2 HF1

Peripherals:
- Honeycomb Alpha
- Honeycomb Bravo
- CH Rudder Pedals
- Corsair K95 keyboard
- Logitech G600 mouse

Addons installed at time of tests:
- PMDG: 744, 748, 738, 739, BBJ1, BBJ2
- Flysimware: Lear 35, Falcon 50
- Leonardo: MD-82, MD-83, MD-88
- FSDreamTeam: GSX/GSX Level 2, KSDF
- Fightbeam: KDEN
- Aerosoft: PANC
- Freeware KONT
- ORBX: Global Base, openLC North America, KEGE, KJAC, KMRY, KSJC, Libraries, ObjectFlow
- SODE
- Active Sky v7900 (have tried 7877 and previous versions)
- Simbrief Downloader
- Vpilot
- SimToolkitPro
- Navigraph FMS Data Manager (charts is NOT installed, no is their simlink)
- Honeycomb Configurator (latest v2.1.0 or whatever it is)

One important note is that I have had this issue on the Leonardo MaddogX, as well as PMDG products, so I don't think this is unique to PMDG. I have not had an issue with the Flysimware aircraft, which are comparably much more simple than the PMDG and Leonardo products. Perhaps the more complex aircraft hold some sort of clue? I have tested without ActiveSky and SimToolkitPro running, made no difference. And I have had this issue occur with no discernable pattern of departure or arrival airports.

Things I have tried:
- Closed all third party addons
- Closed third party software running in the background (iCue, Logitech GHub, etc)
- Disabled Windows Defender Real Time Protection, excluded all addons from Defender
- Installed new GPU drivers using DDU, and have updated to each new version since, all have the same issue
- Cleared shader cache
- Checked drive S.M.A.R.T health for all of my SSD's and verified that they are using the latest Samsung firmware
- Updated all other drivers from official MSI mobo page(AMD Chipset, Realtek LAN, Realtek Audio)
- Updated to latest non-beta BIOS
- Ran the SimConnect console...holy moly there is too much log output to comprehend. Changed the logging level to WARNING, but only a few log lines were generated and nothing when the freezing started.
- Completely uninstalled P3D and all addons and files that are left behind all over the system, then reinstalled
- Ran Memtest 86 and default windows memory tester.
- Replaced non Samsung B-Die ram with the current B-Die F4-3600C16-16GTZN, which is on the QVL for AMD as well as for my specific mobo
- Replaced Corsair RM750 with RM1000x thinking the 3090 may be too power hungry for the 750 watt
- Ran sfc /scannow multiple times, no integrity issues
- Did a Windows 10 in-place repair install
- Uninstalled simconnect and reinstalled latest from the SimToolkitPro dialog.

In response to the hot VRAM theory, I have verified that my VRAM is not overheating using CPUID HWMonitor. In fact, all system temperatures appear completely normal. Also, everything on my system is stock clocked. Except the RAM I suppose, but it's running the factory XMP profile. I was suspicious though, and purchased my current Samsung B-Die RAM, but this did not fix the issue. When the freezing occurs, the GPU usage graph in task manager drops to 0 briefly. I have not looked at the copy graph though. I can't exactly state when this started happening, but it has probably been more that 4 or 5 months. It feels like it has been forever as I can't use my sim for any flight over like two hours.

For testing, I am doing the same route over and over for consistency and aid in the process of elimination, FSDreamTeam KSDF -> Freeware KONT around noon in the PMDG 748. I have yet to complete this flight successfully while testing as the freezes are starting up around 2+hrs into the flight.

This is all the information I can think of, and I feel that our cases are very similar. Right down to the sim being installed on a separate SSD and trying the Simconnect console. I suppose my next test will need to be completely wiping the sim and all addons again, and try a flight with just the sim and one addon aicraft, like the PMDG 748.

[Martyson]

@ AjSkyMan,

How many monitors / tablets?
SimToolkitPro on PMDG flight?
Vpilot / On-line flights in use on problem flights?
Using AI Traffic (default/freeware/payware) on problem flights?
During the problem check the CPU activity (Task/CPU %) in the Task Manager.


“For testing, I am doing the same route over and over for consistency and aid in the process of elimination, FSDreamTeam KSDF -> Freeware KONT around noon in the PMDG 748. I have yet to complete this flight successfully while testing as the freezes are starting up around 2+hrs into the flight.”

Have you tested a default startup (F-35A at KRND) flight to a default destination airport without Add-ons running?

[Bozo92]

Ryan and Aj, same issue here. Observed over dozens of flights utilizing all sorts of add-on/default aircraft/sceneries etc. always a smooth sim, until suddenly in cruise or after landing at destination, periodic and very noticeable micro stutters.

This only began manifesting in HF1. I have discussed this with multiple experienced P3D users (with high end systems) and all of them of them are experiencing the same.

To narrow this down, I downgraded back to the V5.2 client and the micro stutters never appear. It simply cannot be reproduced. The bug is exclusive to HF1. I wouldn’t mind staying with v5.2 but the HTML5 menu freeze is quite frustrating, even when I limit it to only when I open my GSX menu (this is why I updated to HF1 in the first place).

After months of documenting and observing the sudden micro stutters appearing in HF1 sessions, I may finally have found a potential solution today:

In v5.2 HF1 Prepar3D.cfg under [DISPLAY] change SwapChainVSyncOnlyMainWindow=1 to

SwapChainVSyncOnlyMainWindow=0


Please test your typical scenarios and advise if you see any improvement? i.e. no sudden micro stutters appearing anymore.

No sudden micro stutters today flying two sectors (four hours) in the FSlabs (without a restart of P3D in between). Prior to setting =0 the micro stutters would always appear in cruise or after landing in HF1.

FYI, up to v5.2 this was not a setting in the .cfg at all, and therefore it defaulted to =0 versus =1 in HF1.

The setting was added by LM in HF1 because some v5.2 users were experiencing a FPS loss when using Vsync with undocked windows.

The new HF1 default setting =1 should only impact the behavior of Vsync when using undocked windows but it is very possible it’s causing these micro stutters now in even when you don’t have undocked windows (which is my case). Single 4K monitor, 30Hz, P3D FPS unlimited, Vsync ON and always stable 30 FPS (even when the micro stutters suddenly appear).

FOr reference, my system: i9-9900k HT OFF (8 Cores @ 5.0Ghz), RTX3080Ti, M.2, 32Gb RAM

[AjSkyMan]

@ AjSkyMan,

How many monitors / tablets?
SimToolkitPro on PMDG flight?
Vpilot / On-line flights in use on problem flights?
Using AI Traffic (default/freeware/payware) on problem flights?
During the problem check the CPU activity (Task/CPU %) in the Task Manager.


“For testing, I am doing the same route over and over for consistency and aid in the process of elimination, FSDreamTeam KSDF -> Freeware KONT around noon in the PMDG 748. I have yet to complete this flight successfully while testing as the freezes are starting up around 2+hrs into the flight.”

Have you tested a default startup (F-35A at KRND) flight to a default destination airport without Add-ons running?

Thank you for taking the time to read my wall of text @Martyson. I knew I would leave out important info :)

1. I am running two monitors, no tablets. P3D runs on main display and secondary display is for charts / other applications.
2. I have had the issue occur with and without SimToolkitPro running on the PMDG 748 test scenario.
3. I have experienced the issue both while connected to Vatsim via vPilot and while disconnected. In my current testing scenario, I am not running vPilot.
4. I do not use any AI traffic. All sliders for all types of traffic are set to 0.
5. During the issue, CPU activity appears normal. Core 0 has very high usage, up to 100% for long periods of time, and the other cores have varied usage.
6. I have not let the default scenario run for a long period. I will attempt testing with a vanilla P3D install if Bozo92's suggestion does not fix the issue.

Ryan and Aj, same issue here. Observed over dozens of flights utilizing all sorts of add-on/default aircraft/sceneries etc. always a smooth sim, until suddenly in cruise or after landing at destination, periodic and very noticeable micro stutters.

This only began manifesting in HF1. I have discussed this with multiple experienced P3D users (with high end systems) and all of them of them are experiencing the same.

To narrow this down, I downgraded back to the V5.2 client and the micro stutters never appear. It simply cannot be reproduced. The bug is exclusive to HF1. I wouldn’t mind staying with v5.2 but the HTML5 menu freeze is quite frustrating, even when I limit it to only when I open my GSX menu (this is why I updated to HF1 in the first place).

After months of documenting and observing the sudden micro stutters appearing in HF1 sessions, I may finally have found a potential solution today:

In v5.2 HF1 Prepar3D.cfg under [DISPLAY] change SwapChainVSyncOnlyMainWindow=1 to

SwapChainVSyncOnlyMainWindow=0


Please test your typical scenarios and advise if you see any improvement? i.e. no sudden micro stutters appearing anymore.

No sudden micro stutters today flying two sectors (four hours) in the FSlabs (without a restart of P3D in between). Prior to setting =0 the micro stutters would always appear in cruise or after landing in HF1.

FYI, up to v5.2 this was not a setting in the .cfg at all, and therefore it defaulted to =0 versus =1 in HF1.

The setting was added by LM in HF1 because some v5.2 users were experiencing a FPS loss when using Vsync with undocked windows.

The new HF1 default setting =1 should only impact the behavior of Vsync when using undocked windows but it is very possible it’s causing these micro stutters now in even when you don’t have undocked windows (which is my case). Single 4K monitor, 30Hz, P3D FPS unlimited, Vsync ON and always stable 30 FPS (even when the micro stutters suddenly appear).

FOr reference, my system: i9-9900k HT OFF (8 Cores @ 5.0Ghz), RTX3080Ti, M.2, 32Gb RAM

@Bozo92 Thank you for this information, it is much appreciated. I am not using any undocked windows either, however I am not using vsync nor the P3D FPS limiter. I am limiting to 60fps in the Nvidia control panel. I will give the .cfg change a try, and if it doesn't work, I'll disable Nvidia FPS limiter and switch to using vsync in P3D and see if that helps. Will update as soon as I have time to test.

[Bozo92]

Good luck AJ!

P.S. don’t let anyone talk you into wiping your whole OS or sim. Always the same two users here who spam literally EVERY single thread with that very suggestion. Makes no difference and is a guaranteed waste of time.

It happens on a vanilla installations of HF1 and it also happens when using multiple add-ons. What I know for certain is that happens only in HF1 and the longer the sim runs the more apparent the performance impact is.

I have spent countless hours observing, documenting and testing every possible combination. I have no doubt whatsoever that it I began with and is specific to HF1. At some point the application simply does not perform like it first does when you launch the scenario.

There are many threads across multiple forums in which HF1 users observe stutters or a decrease in performance beginning in cruise and/or after landing at their destination.

I have tested multiple scenarios three dozens times in v5.2 and again HF1 and the difference is like day and night.

Something changed between the two version and one possibility is what I shared above.

After reverting to the v5.2 VSYNC behavior by changing the aforementioned .cfg entry to =0 I have not been able to replicate the micro stutters in HF1 or observe any gradual loss performance. Just completed my third flight and I was once again experienced the same fluid/smooth 30 FPS at 30 Hz with VSYNC experience I always had prior to updating to HF1.

[AjSkyMan]

Okay, so the test with SwapChainVSyncOnlyMainWindow set to 0 ran for about an hour before issue. PMDG 748 KSDF -> KONT
I will try disabling the Nvidia frame limiting and use the P3D limiting and vsync.

Also, here is a video showing what the issue looks like and some performance graphs.
https://drive.google.com/file/d/1kLLdE6 ... sp=sharing

I absolutely agree, I shouldn't need to reinstall my OS to fix a bug with an application. And based on what Ryan said, even though he took one for the team and did a fresh Win 11 install, the issue was not resolved.

[Martyson]

Good luck AJ!

P.S. don’t let anyone talk you into wiping your whole OS or sim. Always the same two users here who spam literally EVERY single thread with that very suggestion. Makes no difference and is a guaranteed waste of time.

It happens on a vanilla installations of HF1 and it also happens when using multiple add-ons. What I know for certain is that happens only in HF1 and the longer the sim runs the more apparent the performance impact is.

I have spent countless hours observing, documenting and testing every possible combination. I have no doubt whatsoever that it I began with and is specific to HF1. At some point the application simply does not perform like it first does when you launch the scenario.

There are many threads across multiple forums in which HF1 users observe stutters or a decrease in performance beginning in cruise and/or after landing at their destination.

I have tested multiple scenarios three dozens times in v5.2 and again HF1 and the difference is like day and night.

Something changed between the two version and one possibility is what I shared above.

After reverting to the v5.2 VSYNC behavior by changing the aforementioned .cfg entry to =0 I have not been able to replicate the micro stutters in HF1 or observe any gradual loss performance. Just completed my third flight and I was once again experienced the same fluid/smooth 30 FPS at 30 Hz with VSYNC experience I always had prior to updating to HF1.

@ Bozo92 ,
"P.S. don’t let anyone talk you into wiping your whole OS or sim." Always the same two users here who spam literally EVERY single thread with that very suggestion. Makes no difference and is a guaranteed waste of time. "

Who mentioned wiping the whole OS or sim ?

"Always the same two users here who spam literally EVERY single thread with that very suggestion. Makes no difference and is a guaranteed waste of time. "
Have you reported the spam and had it removed?