But there are three places where the data can be (in addition to CPU registers and L1/L2/L3 cache of course):
DRAM as part of a program’s working set; this is what is reported as “in use” by that process in various process viewers,
cached to DRAM as committed memory not part of the working set,
swapped out to a swap file on disk as committed memory not part of the working set.
I don’t think there is a way of telling how much is in 2 versus 3; tools like Windows Resource Monitor gives 1 (working set) and 1 + 2 + 3 (committed); (committed) - (working set) = (1 + 2 + 3) - 1 = 2 + 3, but we do not know how much is 2 and how much is 3.
With perfect memory management accessing data from 2 is just as fast as accessing data from 1; data does not have to physically move anywhere, it is just a matter of remapping some physical DRAM from being in 2 to being in 1, which is done by the MMU in parallel to all other work without slowing anything down. If that were the case capping the working set to 6.5 GB to fit in XBox would have no performance impact at all for PC users with a lot of DRAM.
But memory management is not perfect. Thus the questions for the more knowledgeable:
A: Just to confirm that 2 actually exists; if the working set is artificially capped, which might be a corner case (I don’t know), is the memory management clever enough to keep the data in DRAM as committed non-working set data or is that use case so rare that it is not optimally implemented?
B: In real life, does it take longer to access data from 2 than from 1, and in that case how much longer?
Well yeah except page tables and TLB and what not need updated too, if that is done in parallel there is no access time impact, but if some of that work is serial there is some performance impact.
Except the bit that is done by the CPU in hardware, such as virtual to physical memory address resolution
Not the case… Open Task Manager, select Performance tab, click Open Resource Monitor at the bottom, select Memory tab, select the FlightSimulator.exe process to filter on it. You will see Commit for that process going well above 6.8 GB even though Working Set stays below that number.
Thank you for being reasonable.
For me all that matters is the final outcome of performance, which with SU5 has improved more so then ive ever seen in my 30+ years using computers, and nearly all issues people have regarding so called downgrades have been addressed and were not intended and should be fixed soon enough.
After everything that has been posted, by users and the developer, there has been BOTH an increase in performance AND a decrease in visuals. Stop being so binary people!
It’s really a matter of what’s important to you, what your computer set-up is, etc. I was most happy with this bullet point for the upcoming patch notes:
LOD Popping and Stutter when Camera Panning – PC Simmers with graphics set to Ultra will experience this when panning the camera around very quickly. We are working on a new option that will allow you to customize how much off-screen scenery will be cached. We are aiming for this to be released on August 24th (World Update 6).
i.e. Yes we are limiting the RAM utilization, you are not imagining it!
Your summary is very good. The only comment I have is that application memory requests are very dynamic. If MSFS needs more memory to load textures and objects for an airport, it will grab more memory and Windows has to manage it. Well-behaved programs release memory when no longer needed. This working set changes can be displayed by Task Manager for each process.
You can increase ram usage by using ramcache software then you can tell it to use as much RAM as you want. Might try it out again later see if makes any difference.
You say that but to my surprise it actually did improve things for me had even less stutters and gained a few fps, before the update that extra fps was needed as my i9-9900k and rtx 2070 could only just manage around 30 fps with many settings lowered including not using live weather.
Confirmed at least for me the sim is only using 6 odd GB of CPU ram but I do find vram behaviour interesting (all 2GB of it for me) as it seems to be pegged to 30fps. I have vsinc disabled but can say precisely that above 30fps I am under budget and anything below 30fps I am over budget … not so strange you might think however I am seeing no sudden drop off as I go over budget, as far as I can perceive the curve all the way down to 20 is quite uniform without any stuttering, I know frames are being dropped but without sudden movements I just can’t see them. Compared to before the update that is a stark difference.
My stand on this CPU memory thing is that if they really want to make this the best sim since sliced bread they will have to develop some parts separately to Xbox however, unless it’s for cache, it won’t ever use more than 16GB in game as there just isn’t the need although a cabin full of animated passengers might change this.
