Hi there, just want to share my observations here, in case anyone else encounters this.
(mods pls merge if double thread, i searched and found nothing that matched closely)
(tldr; if you have extreme stutters and freezes with photogrammetry, try turning the rolling cache off)
PC: Ryzen 5 5500, RTX 3060, 16GB RAM @ 2560x1600 resolution. Can run sim limited to 40FPS (i don’t need more in a sim and it saves power and heat and noise, ymmv…) with high to ultra settings in most situations.
Sim has no addons.
I just approached LPPT in the a320 and when the Lisbon photogrammetry began to load the sim began to stutter extremely with 2-4 secs freezes and 2-30 FPS inbetween. It was unflyable, had to canel the approach. This was the first approach with a PG area near, so i never encountered this before.
Internet search to no avail.
My internet speed should be fast enough having 100MBit.
Really thought “OK, thats it for me, can’t longer use the sim since this is unflyable”.
Then i realized that the HDD acces light was blinking like crazy all the time during this lag situation (though i got an SSD capable of writing and reading about 500MB/s, so this heavy access shouldn’t even occur). That got me thinking “what if it tries to update and rewrite the rolling cache all the time and cannot keep up or something” since i have it on and set to 16GB.
That did it!
Turned the rolling cache option completly off, retried the approach and had 35-40FPS all the time with no stutters or freezes and really beautiful Lisbon photgrammetry (for those never flown it - try it, it’s really beatiful).
Lisbon is stunning, so much so I was gearing up for some TAP ops in my busses but alas the only available airport for Lisbon triggers the blank avionics bug. I really hope that’s fixed soon, preferably before 2024. Ha maybe the new game will just be 2020 with added usable avionics!
Using rolling cache only has sense when you intend to fly offline in a particular area you have previously cached and stored on your HDD. MSFS won´t even require your full network bandwith during regular flying unless you have a really low speed network. It downloads the initial scene just once while the flight loading screen is active, so there is when you may eventually find a full bandwith usage. But afterwards it just updates the new scenery data as you fly. For that it may use around 10-20 MB/s for just a few seconds while in the download peaks and that happens every few minutes only. Indeed the minor updates and rest of online services are progressive and just need something below 1 MB/s to be updated.
Absolutely concur on the bandwith thing. I configured afterburner so it can show the D/L rate in the overlay. With this i can realtime monitor MSFS’ downloadrate an as you say it peaks during loading and sometimes during game, but over the time it is no more than a few 100KB/s for streaming the bingmaps or some 1-3MB/s when flying over not cached PG areas.
Of course this depends heavily on the moving speed. Slewing with max speed over PG area maxes out my 100Mbit^^
Thank you for this!!! Disabling rolling cache 100% fixed the massive stutters for me, too! (This is on a 7950X, 64 GB RAM, 4090 RTX.) It’s ironic that enabling rolling cache on a fast NVMe SSD has the exact opposite effect of what a cache is supposed to do, lol.
MSFS Rolling Cache performance is a mystery to me. Generally users have it on or off. I think there might be a “sweet spot” for optimization of the cache different for each user. I’ve experimented changing the cache size. The standard size of 32 GB was too big for me. I tried 16 GB which was better and have reduced it to 10 GB. I am trying to find the point where more data is being read from the cache than is written. The manual cache is optimized in the sense that no data is written to the cache during flight.
I have tried turning off the rolling cache but my network connection speeds to the MSFS servers vary quite a bit and are very random. I would get random periods of delay or stutters. My smaller rolling cache seems to have helped but it isn’t 100% perfect.
I can’t understand how it works either. With rolling cache ON, i got 0 - 1 FPS in Vegas, after delete the rolling cache and turned it off, I got 60 - 90 FPS (DSLL, 3400 px with downscaling), go figure. Without photogrammetry, the rolling cache On or Off doesn’t seem to make difference (good FPS either way)
Rolling cache is only necessary if you have a data cap and fly often. My daily data usage averages 15GB per day using rolling cache, 40 with it off. With a 1.2 TB monthly data limit I either use it, or don’t fly. I hate it but use it.
Thanks! It worked for me. Both ways, turning the photogrammetry off or leaving it on and turning the rolling cache off. The later option is definitely the better option when you want to look at more realistic versions of the buildings. The first option is better if you want to have better-looking buildings and don’t care about a depiction based on the real ones. With the rolling cache off, I have to hover a few seconds over an area until a high-resolution image of the building has spawned in. In the beginning I just have some washed out blobs.
Anyway, both ways are solving the huge lag issue. It was especially bad because it occurred only near ground, where smooth performance is immanent so you don’t crash into the ground. Strange that a cache is the reason for lags; I am sure that is an issue/bug that could be fixed in an update. But anyway, I am very happy that MSFS is now playable for me again!
