I use Resource Monitor and ProcMon64 to track disk usage and network usage.  I can track individual I/O operations (Disk reads and writes) so it is easy to see how cache is being used. 

I have 128GB rolling cache on a dedicated NVMe device.

When I fly in a new area I see a lot of network traffic and a lot of writing to the rolling cache.

When I return to that area (next session so nothing else gets mapped to the cache) - I see almost NO network traffic and a LOT of reads from the rolling cache.

I am not very confident that loading is faster nor is the frame rate improved - but at least I am not so dependent on the cloud.

Recently (last two weeks) I have been flying exclusively in the area from Olympia, Washington to the San Juan Islands between the Olympic and Cascade mountains.  After a week or so of flying there - I seldom see network traffic and do see a lot of rolling cache reads. 

That is an area ~150-miles by 50-miles and it seems to all stay in cache. 

Edited January 13, 20251 yr by TacomaSailor

5 hours ago, jcomm said:

RollingCache.ccc performance debugging and tuning … How? - User Support Hub / Install, Performance & Graphics - Microsoft Flight Simulator Forums

I have mine set at 64GB but after reading the above, I wonder if t's really worth even setting it away from the default 16 GB 😕

wow that's a deep dive, but indeed i'm not sure if just increase the size is the solution for most optimal efficient caching. 

I flew KPSP to KLAX and back. Cache set to 100GB. Photogrammetry enabled. 

En route to KLAX, past the LA CBD I got massive stutters, same for the return trip (network download up to 100Mbps). Closer to KPSP (return trip), download up to 30Mbps with disk read and write up to 5MB/s. 

So... why the download and disk write on the return trip? Assuming that rolling cache should be beneficial when flying in the same area, this doesn't make sense. What am I missing here?

In terms of the download up to 100Mbps and severe stutters past the LA CBD, this also doesn't make much sense. I just tested the internet speed, it's 644Mbps. The stutters could of course be caused by performance limitations - although most of the flight I didn't have any issues, even when overflying LAX at 2000ft with a TLOD of 600. 

Btw, I flew around the Bahamas region for about an hour and got an average download speed of 3.2Mbps. I'll test this over a densely populated area - could give some indication of what cache size to use. If the rolling cache is even working...

I wasn't using the internet for anything other than simming for the tests. 

Edited January 14, 20251 yr by Cpt_Piett

Ok, so rolling cache makes less and less sense. I'm on my 3rd flight from Cardiff to Heathrow (around 100nm). And for some inexplicable reason, there's a LOT of writing to my cache SSD. Why? Maybe 100GB is insufficient for this flight, dunno, confused...

In addition to this I'm getting a LOT of stutters at FL100, even though performance headroom is more than enough (TLOD50, FPS around 100, frequently dipping to less than 70). 

I'll increase rolling cache to 400GB and repeat the flight - don't have space for much more. 

Edited January 14, 20251 yr by Cpt_Piett

18 minutes ago, Cpt_Piett said:

Ok, so rolling cache makes less and less sense. I'm on my 3rd flight from Cardiff to Heathrow (around 100nm). And for some inexplicable reason, there's a LOT of writing to my cache SSD. Why? Maybe 100GB is insufficient for this flight, dunno, confused...

In addition to this I'm getting a LOT of stutters at FL100, even though performance headroom is more than enough (TLOD50, FPS around 100, frequently dipping to less than 70). 

I'll increase rolling cache to 400GB and repeat the flight - don't have space for much more. 

What happens to the stuttering if you disable the cache?

9 minutes ago, flyingscampi said:

What happens to the stuttering if you disable the cache?

I don't think it's possible to disable it - maybe the minimum is 16GB, not sure. 

For some reason, on my 4th flight now EGFF-EGLL, everything is smooth as silk, exactly the same settings. Rolling cache is now 400GB, and there's a lot of writing to my cache SSD, and a lot of network downloads. So I guess the rolling cache needs to be "filled up" after changing it to 400GB...

Am I alone in spending more time 'faffing' about with ~24 than doing any flying? I'm caught in a cycle of 'I wonder if this works' or 'I wonder why this doesn't work' Occasionally I hit a 'Yay! That works!' Having sorted that out, I go and watch a movie. Another work day over. 😂

35 minutes ago, Ron Attwood said:

Am I alone in spending more time 'faffing' about with ~24 than doing any flying? I'm caught in a cycle of 'I wonder if this works' or 'I wonder why this doesn't work' Occasionally I hit a 'Yay! That works!' Having sorted that out, I go and watch a movie. Another work day over. 😂

You're not alone! Having a day off from work, I'm trying to get to the bottom of the rolling cache mystery. The more I test, the more confused I get haha 😅

Regarding how many time do we really simfly? My passion for flight sim could be split in 3 since MSFS2020. At first, it's the sim-flying experience itself. And second, the sim is a non-stop evolving phase and fixing, not to mention benefiting from the ecosystem and the community. Since MSFS2020, I've added the scenery development. 

I don't know about the split, but I would love it could be a 1/3 of FlightSim, 1/3 of evolution/patching/fixing/enhancing and 1/3 of free airport development.

Edited January 14, 20251 yr by vbazillio

Increasing the cache has helped with smoothness overall for me in 2024 - I went for 64g from 16g to start just to see and there is some improvement.  Might go a bit higher but I really dont want to over do it.   And agreed I hate being back in test setting and play mode - which I was hoping to avoid as I no longer have the patience for that stuff - I just want to fly.......

In network settings->advanced->data usage you can see how much data the sim has used.

I'd set my cache size based upon that.

2 hours ago, Ron Attwood said:

Am I alone in spending more time 'faffing' about with ~24 than doing any flying?

What are you faffing about with?  I was always faffing about in 2020 for the whole four years it was out.  2024 has been a completely different story for me after the first week.  Load up, fly, shut down for the most part. 

8 minutes ago, JSmith2112 said:

In network settings->advanced->data usage you can see how much data the sim has used.

I'd set my cache size based upon that.

Didn't know, thanks for the suggestion. I've been using task manager to monitor network download and disk read/write. 

Well, after flying EGLL-EGFF back and forth all day, I'm no wiser than before 😕 Even with a cache set to 400GB, there's not much reading from disk flying over the same area. I could repeat the flight with a cache set to 16GB but I can't be bothered to do more tests haha... 

1 minute ago, MrBitstFlyer said:

What are you faffing about with?  I was always faffing about in 2020 for the whole four years it was out.  2024 has been a completely different story for me after the first week.  Load up, fly, shut down for the most part. 

I think we're just trying to figure out how stuff works, and how to get the best performance 🙂

Hmm, that thread mentioned by jcomm earlier is making it sound like the cache isn't performing too well - caching things that maybe shouldn't be cached, not caching things that should be cached.