It is pretty obvious that everything has to load in too late, which means that it comes from not being pre cached.
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Ehhh … no. Really: not at all.
In particular, blurry or popping textures during final have really absolutely nothing to do with the Off-Screen Cache. The cache caches the invisible parts of the screen: during final, the parts behind the plane. I’m pretty sure, if you see popping textures during the final, they are not behind the plane.
Based on my testing, the off-screen cache resides in system RAM. Bumping the setting up consistently increases RAM usage in my case, and I imagine for everyone. It was one of the many optimisations that Asobo introduced with SU5 to make the sim fit within the memory budget of the Xbox Series S|X.
As for the VRAM management, I think it is likely that depends on the user’s GPU. For me it is almost full most of the time, so panning the camera will cause VRAM usage to fluctuate a lot, and it can cause some stutters even at the Ultra setting. But for GPUs with higher VRAM amounts, the sim may choose to keep a copy of the cache on the GPU at all times. In fact, there was a bug in FS2020 (might still be there as of SU16, but I can’t check myself) where enabling FSR 2.1 would disable VRAM management and cause overflowing on GPUs with smaller memory amounts.
If a part of the scenery in view is not in the off-screen cache, then it will be pulled from the rolling cache, and if it is not there either, it will be streamed anew.
Again though, according to my observations there isn’t any indication that the off-screen cache isn’t working properly in SU4. The difference in scenery loading speeds is still rather significant between each off-screen cache setting. I continue to insist that what is being described in this thread is rather a camera bug, which could also be connected to this.
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In 2020 I can see substantial difference in FPS while panning camera between off-screen pre-caching low and ultra. In 2024 I can’t see any difference at all.
For example, in 2020 at default Zurich (handcrafted) with Fenix A320 FPS is around 30 and drops to 27 while panning fast. Off-screen pre-caching at ultra.
In 2024 the base FPS with same aircraft and location with identical settings is around 37 but drops to 23 while panning.
PC specs:
R7 5700X @ 4.7 ghz
32GB RAM
RTX 3060 12GB
This has nothing to do with the pre-caching. Of course FPS will decrease by a certain amount during panning, since there is a lot more load on the GPU. But that is a constant decrease and no stuttering.
The pre-caching prevents loading objects to VRAM and therefore short but heavy FPS drops.
I hope this issue will be resolved in SU5 beta. Because its so weird that they released SU4 with this broken option they caused themselves in SU4 beta
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I don’t understand. If scenery is pre-cached to VRAM, and VRAM is 10X DRAM speed, then why is there any lag when changing camera views that should be pre-cached?
Reading from a fast cache shouldn’t affect FPS at all. It’s the very reason for caching.
It seems as though switching camera views causes assets to be re-streamed instead of read from VRAM.
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There is no lag if it is pre-cached in VRAM. The lags occur as soon as the cache was removed from VRAM.
There are meanwhile several other threads dealing with stuttering after a certain time of inactivity. In SU4 it seems to be 20 seconds, in SU5 60 seconds. The result is always the same: after a certain time of inactivity you can see VRAM is freed by several GB. Starting panning leads to stutters. After the first 360 degrees turn, the VRAM is filled again and the following turns show no stutters anymore until the next phase of inactivity.
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This is what happens when the off-screen cache is disabled (closest equivalent would be the Low setting), you can see the scenery streaming again over a couple of seconds. When it is enabled, there is at least one frame of delay, presumably to avoid placing too much work in a single frame (that could cause a heavy stutter).
Is this also the case with high-VRAM GPUs as well? Like 24GB or more?
I’ll test this. My 3090 Ti has 24GB VRAM.
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That is the very frustrating point. This purging is always going on, in total disregard of the VRAM available.
Problem persists for months now, several threads about this, hundreds of votes, SU5 beta 2 flighting and nothing has been fixed.
This is a game breaking fault of the engine, yet no official statement from neither MS nor Asobo, no new developer stream since 10/2025 either.
Sadly, something is very amiss here…
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I wonder whether the DX12 programming is being done according to the very complex rules outlined in this article:
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Well since a mod mentioned this is the corresponding report for Off-Screen Terrain Pre-Cache failing..
I’d like to confirm that it is not working at all in SU5 Beta 1.7.10
We hope this issue gets fixed prior to SU5’s release.
Thank you.
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I also have this problem across SU5 Beta.
Those stutters are stronger on the ground than in the air.
It really ruins the fluidity despite having 40-60 FPS without Framegen. I hope this gets fixed as this is a major immersion killer.
2 Likes
It’s hard to say for sure, but in the above two videos it seems like frames are being discarded when camera movement gets too fast. When I think of ‘stutters’ I think of a hesitation from one frame to the next. All the frames are being written and displayed, but it’s taking extra time to process them (i.e. interframe latency.)
In this case it appears that frames are being dropped altogether in order to reduce interframe latency.
In Screen recordings, the issue does not come across as bad as it actually is, because the related mouse input is missing. In reality, you would move your mouse to pan your view to an instrument, switch, look outside, etc, and notice at the same time, that the view does not change in a linear fashion, but rather it freezes and jerks, until the VRAM has been recached.
Considering this, the recordings @Tweak112 showed, do very much resemble my own experience
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Yes, that is one aspect. The second is, virtual memory is at the limit.
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I haven’t experienced any stuttering throughout the SU5 Beta. Here’s a video from the latest version of SU5 beta 1.7.10.0
Zero stuttering.
KLAX
NVIDIA Control Panel settings
Global settings - default
For the MSFS 2024 profile in NVIDIA control panel, I only change three settings: Power Management Mode to prefer maximum performance, limit Max FPS to 60 (120 or 200 FPS won’t make me a real pilot - 60 is more than enough for virtual flying and there’s no need to stress the hardware)
VSync - I have it set to Use 3D application settings and in MSFS settings I have it turned on.
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