I've used them plenty. I actually have a comparison video here from FS2020 when they introduced aggressive culling to save memory.
(They added an option later to reverse this as copying from RAM disk to RAM is still slower than just keeping it in memory)

This is actually between streaming and RAM disk (150 mbps connection)

Streaming:


Cache on RAM disk


I've used RAM disks since the late 90s until games got very big and memory hungry. Then used it again for FS2020 after I upgraded to 32GB ram. Reserve 4 GB for the cache.

Results vary of course as Windows does a lot of caching in RAM already. Hence PC doesn't need the fastest SSDs as a lot of things that get accessed multiple times stay in RAM. Atm Windows reports 4.3 GB of RAM on standby (cached data and code) and another 620 MB modified (but not yet comited to disk)

As you said. PC's have the luxury of generally having a lot of extra RAM available. It doesn't go to waste. Consoles don't have that.

It's diminishing returns.

...And I did call it before this console generation started, when everyone was fornicating over the PS5's SSD... It wasn't going to enable experiences not seen elsewhere, which has absolutely remained true.

Sony should have went with a slower SSD and went with a larger SSD.

Or invested more into their SoC for better graphics.

From what I can tell they are moving the rolling cache that is typically on the HDD/SSD into RAM rather than having the entire games install in Ram... I admit I am not exactly knowledgeable when it comes to flight simulator.

It's not the same as having everything installed into Ram... I have 256GB of Ram so I could get away with it for most games.

The full story is, FS2020 first used around 20 GB of RAM while flying, using the Windows pagefile to have more memory (slow). Then they did the update to launch on XBox which was mostly aggressively culling RAM use so the game would run with max 12GB RAM in use.

Yet that meant that every time you look around, the data is already gone and it has to stream it in again, either from the server or a rolling cache on HDD/SSD. The rolling cache storing data you've already passed in case you turn around (or look behind you) and pass over it again later. You can set it as big as you want so for example you end up with all of London on your HDD/SSD as you circle around. But keeping it small and place it on a RAM disk turned out to be much faster then storing more data on SSD.

Rolling cache on RAM disk is still slower than 'forcing' FS2020 to keep more data in RAM at all times. You still have that overhead of finding and updating data in the cache and copying from RAM to RAM to VRAM. Consoles are a lot smarter that way.


In your case, even if you allocate a 128GB RAM drive to fit entire games on, I think it's still faster to simply launch from SSD instead of copy game from SSD to RAM disk and then launch it from RAM disk. Once it's on the RAM disk further data streaming in game should be faster, but probably rivaled by Window's own caching.

I don't know how Windows determines how much to use (now 7.7GB cached, 7GB in use, 24.5GB free) but Windows mostly does all the balancing for you. You just want to avoid heavy use of the pagefile on disk, that's what slows everything down. (Hard Faults / sec in the memory resource manager, keep that low to 0)


I've done tons of profiling on FS2020 for example


Here FS2020 has 41 GB in use, but only 7.7 GB working memory. The rest turns out to all be in the page file waiting to be committed to the rolling cache. So not a real memory leak, the problem with the game at the time was, it didn't allocate enough time for garbage collection and just left old data sitting in an ever growing queue to be either discarded or written to the rolling cache. I've had the game up over 60GB in use before it gave up and crashed. Page file full, game over. (It's all much better now, this is from the first year of FS2020)

But it does highlight all the layers with PCs

Data goes from Disk/Server -> System RAM -> VRAM -> Discard Queue (system RAM) -> Rolling Cache (Disk) with Windows keeping some data in RAM cache (Standby) and/or disk cache (pagefile.sys) as well.
Console it's simply Disk/Server -> Single pool of RAM


Anyway can't have all of FS2020 installed in RAM, 2 peta bytes worth of data lol. Turning the rolling cache off solved a lot of problems at the time, simplicity always wins. (Until aggressive culling was forced as default to fit the game on XBox)

Instant loading into areas. Fast travel in The Witcher 3 is instant transmission. Playing vlair obsvur now which has a lot of instanced areas you have to "load" in and out of and this could mena 10 second loading screens on a SATA drive, maybe more but here it's a flash, litterally saving dozens of hours adding them all up over the year, gets rid of all frustration and essentially leaves you with more time to play games. I doubt that can be done at 600mps. Even two have 5 seconds of a black screen would tick me off now. Blavk Myth wukong had about 15 second load times when fast traveling and I was actually pissed off at that after a few months of PS5. As a trophy Hunter who goes a light speed while cleaning olup trophies and speed running games this is a magical thing for me. No migraines, no irritation from the constant interruptions, no putting the controller down and waiting. Just right there, no immersion break. It's brilliant. No more squeezing trough tight crevices for 10 or 15 seconds to hide streaming assets. 

Read the comments below for peoples experience. TL;DR lots over stuttering on HDD and SATA. 

Yeah the PS5 could've been balanced somewhat better. AI should be the main focus for the PS6 and that'll make a way, way bigger difference since upscaling will help out that console massively. I could see it having frame gen as well as a way to let loads of games offer 120fps modes.

It's gotta be mainly because of inflation and a rich orange prunes starting a trade war with the rest of the world.