So how does it work (if it works) ? 

Does it download synthetic scenery ? Does it download only photogrammetry scenery ?   What does it caching really ? Does it always cache in 'High' quality ? 

Does it keep downloaded data after closing the sim, ready for the new session? 

4 minutes ago, Steku said:

Does it keep downloaded data after closing the sim, ready for the new session? 

Yes, it keeps the downloaded data until it reaches the rolling cache limit.  Once you reach the allocated rolling cache limit, and you fly into a new area, it will start to overwrite the old cache to maintain the cache storage limit.

4 minutes ago, Tierborn said:

Yes, it keeps the downloaded data until it reaches the rolling cache limit.  Once you reach the allocated rolling cache limit, and you fly into a new area, it will start to overwrite the old cache to maintain the cache storage limit.

So does it download synthetic scenery ?

AFAIK, and this is somewhat conjecture based on how caches are supposed to work and my own observations, is that the rolling cache caches everything, but it will only download data that is a "cache miss", so if you're flying the same routes over and over, that scenery will load directly from the cache and not the Internet. If you go on a cross-country flight and fill your cache, then it will replace the oldest data with newer data.

My only question is if it acts like a CPU cache, where it it's the L2* cache and the manual cache is the L3 cache. In other words, will the rolling cache copy data from the manual cache? They are two different files (possibly on two different drives), so it is conceivable. In fact, I had to delete both my manual and rolling caches to fix a scenery glitch, which makes me think this is indeed the case (I cleared the manual cache first but it didn't help).

 

* I suspect there's a RAM "cache" as well, which is analogous to the L1 cache, in that everything you can see (and not just on screen during a specific frame, but in any direction) is kept in RAM at various levels of detail. Otherwise we would have serious stuttering and / or pop-in. Now whether MSFS does this or whether it relies on the OS's cache is beyond my expertise. Though giving it some thought, MSFS must do this since we can play with zero drive caching and still have a smooth experience.

Edited October 7, 20205 yr by Keto Ketchup

I’d like to know if older cached scenery gets overwritten if Asobo updates the scenery.

Turn it off and forget it exists, if your connection allows it (and you don't care about the environmental impact of data streaming).

I'm certainly sceptical of the need for, or benefits of, cache for online flying (other than Colonel X's point above). I haven't noticed any change to how things work for me, either way. Perhaps my 38mbs connection is good enough not to need it.

And unless I am completely misunderstanding how to do it, Adding manual cache is a very laborious task. If you want to save an area at high resolution, you need to zoom in on it to an extreme level, then 'paint' the mouse cursor of that area to save it. a small city can take several sweeps of that to cover. Why on earth can you simply use a more distant view of an area, paint that area and then select the resolution you want it save in? It seems back to front to me and could be a much faster process (at least as far as the user side of it goes - the processing would take the same time).

Then there is the file size. It seems non-photogrammetry areas only save as around 1.3mb (though still taking as long to process), so is there any benefit to saving such areas? It seems not. But since the cache map doesn't highlight photogrammetry areas, you don't know if it's worth it until you see the results. As Toyah once sang, "It's a Mystery"!🙄

I find it useful as my internet connection is very haphazard and oscillates violently from between 1.5 Mb/s and 20 Mb/s. I also tend to fly contiguously in the sim; starting from where I landed last session so if my connection is patchy I have Bing Scenery to begin with giving the sim a fighting chance of continuing to provide Bing and not flipping to Offline Mode - which is pants.

What I'm exploring now is to see if that red message box saying; "Your bandwidth is too low - switching to Offline Mode" can somehow be edited so that whatever bandwidth amount MSFS thinks is too low can be lowered still.

That will allow for my crazy up and down internet connection speed.

Edited October 8, 20205 yr by Will Fly For Cheese

50 minutes ago, 109Sqn said:

Then there is the file size. It seems non-photogrammetry areas only save as around 1.3mb (though still taking as long to process), so is there any benefit to saving such areas? It seems not. But since the cache map doesn't highlight photogrammetry areas, you don't know if it's worth it until you see the results. As Toyah once sang, "It's a Mystery"!🙄

That's the weird part, it will show 1.3MB, but it will actually download around 50-100MB