I don’t know if anyone else has this problem or not, but if I do then I guess its happening elsewhere. For quite a long time with the sim I’ve had an issue where if I fly in very specific locations I get massive stutters that sometimes last over a minute or more before settling down.
For example if I fly just north of Miramar in California I get huge stutters. At a certain point in the mach loop in Wales I get huge stutters and at a certain location just outside Stirling in Scotland I get huge stutters. There are other locations too in some of my frequently flown routes of choice where I’m plagued by stutters at a certain point in the route.
Has anyone else experienced this in very phenomena in very specific repeated locations? Is there any solution to it? This isn’t a SU10 issue as I’ve had the problem for a while.
I use the Steam version and fly with terrain cache turned off.
Switch the cache on. Thats what its there for. The first time you fly in an area it might be slightly slower, but there after, its running from your system rather than pulling it over the internet connection.
I fly the Hawker Hunter and JF Hawk in the loop without issues.
I thought the consensus among the flight sim community had long been that if you’ve got a fast internet connection, and I do, then the sim performs much better and with far less stutters with the cache turned off?
That being said I haven’t had it turned on for a long time so I’ve no idea whether recent sim updates have cured the problems with it that there used to be.
Urban myth. The speed of the connection is broadly irrelevant (unless your downloading updates etc). It uses roughly 2-5Mbps in game. The point is that it will load content from your pc much more quickly than it can pull it from the cloud. Even if you had a 1Gbp connection and the server was serving you at 1Gbps (which would never happen) it is infinitely quicker loading that data from your disk / ssd / NvMe etc
Just tried repeatedly flying one the routes I have known issues with the cache back on but there’s no difference. Still massive repeated stutters. Its an odd problem for me if other people aren’t suffering the same issue.
Just tried with all data turned off. No difference. One of the problem areas for me is flying south out of Bolzano airfield in the Italian alps. The area about a minute or so due south always causes me repeated stutters.
Your mainthread is getting hammered, usually from too high terrain LOD for your system. I would lower it to see if it helps, and don’t go above 200. Set your offscreen caching to ultra, as this will help even out some sutters at the expense of higher VRAM usage, which you have plenty to spare.
Off screen caching is at ultra. I usually run terrain LOD at 200% but just tried it at 100%. No difference. Still massive stutters at that one area.
I’ve got a 5600X. The only time I see a difference in FPS with higher LOD is over photogrammetry. Out in the countryside I don’t really see any difference between 200 and 100%.
Usually when you have this massive mainthread spike, it’s due to loading objects. The loading of certain LOD objects is rather inefficient in some areas, and you can get this brief stutters. I rarely experience that myself, but it happens. I’m not sure what else I can suggest except turning down terrain LOD, but clearly even this isn’t exactly a solution.
Thanks for your help. Its odd that its just in very, very specific locations and doesn’t at all seem dependent on CPU load, or things that might over load the CPU.
Its really odd no else here seems to suffer from it. I’m slightly in mind to do a complete fresh reinstall of the whole sim but I’ve gone to the massive hassle of doing that in the past hoping it would cure problems only for it to make no difference.
You can try to do a complete reinstall, but I would not expect it would fix it. Complete reinstalls usually work fine if there’s some type a corruption issue and you can’t physically open the sim.
Just for the record, I do encounter this issue in specific areas as well. For example, outside Denver my system will start those short stutters as the mainthread starts getting hammered for unknown reasons. They’re small and don’t bother me much, but I suppose on lower-end systems this can become more pronounced with longer stuters.
I’ve got a 5600X, RTX 3080 and 32GB of RAM with the sim running off a NVMe drive so it should cope with things ok. I do wonder if its a shader cache issue.
I have the same with Heathrow on 27L short final and towards the middle of the runway. I’m sure these occur because of unoptimized scenery elements, hence same place every time. The cache is no solution for me either.
Sounds definitely possible. The problem is for me is it happens in some locations well away from any hand crafted scenery add on. I get long repeated stutters at the exact same location in the mach loop in Wales each time I fly it. There’s nothing there which you would think would trigger it.
@Mobias7 You’re not alone. I’ve also had this exact issue since SU9. Was hoping SU10 would solve it but it didn’t. So I spent practically the whole weekend trying to sort it out.
Doing laps of the Mach Loop was definitely what made me realise it freezes (2-4 seconds) at exactly the same spots in exactly the same way every single time (every lap).
This post turned out quite long so I will put the end first hahah.
QUESTION: do you run any mods you may have forgotten about that are installed directly from MS Store or Orbx library through symbolic links?
I had FS Birds British isles and deleting that as well as a big tidy up of mods had a big impact. I removed the more worldwide / global affecting things (like We Love VFR, Mamu powerlines, solar farms etc) and reduced TLOD a bit more.
I had forgotten about Birds as I bought it in the marketplace — I think there is something wrong with its efficiency.
This has massively hugely improved things. No more freezes at Mach Loop!! Seems to be a tipping point where there is just too much to monitor for the MainThread for me. Not the most powerful PC I have but it’s strange that it happens on exact same spots in some areas.
—— THE LONG BIT ——-
More recently it had gotten worse but I have been adding more mods. Freezes of up to 15 seconds sometimes but most common was around 6 seconds in some places.
It didn’t seem to matter if I turned down LODs to minimum (10). Turned Graphics to Low or ran no mods (with a caveat of the FS Birds I had forgotten about, and FSREALISTIC). All online data (inc. photogrammetry) and traffic off. Multiplayer off. The same freezes for 1-3 seconds at the same point in exactly the same pattern every time. This was months ago. I made a post about it here (including video of Mach Loop):
Other areas fly totally smoothly always. Locked to my 30fps with all my global mods enabled (about 550 things), High graphics and Ultra terrain cache. I have 900mbit fibre so don’t have rolling cache. So I learned to just enjoy flying those areas and wait for SU10. As that didn’t fix it I went back into troubleshooting mode over the weekend.
The last post by me on that link was just this weekend with more info after deeper testing and rising frustration BUT, this could be the important bit… I finally managed to massively reduce the freezing. Not gone, but I can fly the Mach Loop with zero pauses. Some pauses elsewhere I get now, but usually only 1-2 second and nowhere near as often it seems (I can live with that for now).
What I remembered, after making that last post (before I added an edit at the top). Is that I had bought some global enhancements through the ms-store so when I untick stuff from Addons Limker those things were not really gone.
So I deleted the FS Birds British Isles and West Europe, disabled Mamu powerlines and solar farms, we love VFR region 1 and 2, Mamu wind Turbine replacement and a few others.I’d already disabled GAIST a while ago.
I still have active AccuSeason, Orbx GB POI’s (both), Mamu Marinas, UK Coastline fix, Seafront Sims stuff, FS Realistic, REX Airport Textures, Simple Traffic, PMS and tons of airports (all over the world with a lot in south UK) and planes / liveries enabled and this is mainly now fine.
I suspect the Birds is actually pretty badly optimised for CPU and I could get away with adding a few more of those global things back but after hours of fiddling and testing and reloading and testing I was just so delighted to have fluid flight in all the areas that were being bad before that I have left it like this now. Sad to lose the Mamu stuff but HAD to leave Marinas enabled whatever - that’s essential now!
In summary. It’s not ONE specific mod, it’s a compound issue that just seems to take it over a knife edge when there are too many things coming into range or view at the same time.
Also some photogrammetry (even official world update ones) are a lot more performant than others. All the latest ones are very good. Italy, Spain, even Berlin which is massive is fine. But older ones — UK ones are worse and like Utrecht in Netherlands (which is a small city) was still freezing a bit even after the changes I made. Strangely it would be smooth OVER the city where before it was lagging. Then just when I think “yay it’s fixed” it would freeze for 5 seconds in the countryside!!! (I have no addons around there but there were a lot of marinas items rendered by Mamu - many of the groynes in the rivers there, but they weee behind me so it could be CPU tasks to UNLOAD stiff as well as spawn stuff). So still not totally solved.
It is totally bizarre that it would HANG for up to 15 seconds to recover though. What is it doing?
I have the same problem with the Airport scenery from GAYA at LOWW. If I spawn my plane at LOAV (Bad Vöslau) i got the stuttering always if I look in direction LOWW. With the off screen caching on it will not stutter every time. If I look at the same direction and always stay at the same point the off screen caching seems to work. But if I start to move and try to look again in this direction the stuttering starts again. I think GAYA’s LOWW Airport scenery is the problem and the off screen caching doesn’t work if you have different angels of view to the same direction!
