NO, NO, NO
VRAM is not a general name for any memory used by GPU.
VRAM is a special type of super fast memory built exclusively in GPU.
iGPU has no build in memory, rather it uses part of the system’s standard RAM instead.
4 Likes
@Frank240374 should think of it as video memory and not VRAM
DGPU has video memory = VRAM
iGPU has video memory = system RAM
RAM is much, much slower than VRAM.
1 Like
VRAM is the memory used by a GPU. Some of it is dedicated, some is shared with CPU RAM. You can call it GPU Memory or video memory or GPU RAM or VRAM, just as you like. It changes absolutely nothing. In particular not for the question asked in this thread.
well, then rather reformulate the thread, for your VRAM and VRAM of computer science professionals (in FPS viewer) do not have the same meaning
2 Likes
Apart from your puns: did you contribute anything to the solution?
1 Like
Experiencing same issue, RX 7600 8GB.
I have tried:
- disabling SAM (ReBAR)
- tweaking settings
- reinstalling MSFS
- reinstalling windows
- disabling all addons
- multiple driver versions, cleanly uninstalled with DDU
- restarting graphics drivers when the issue appears
- lowering resolution and render scaling to absolute minimum when the issue appears
None of this has been able to fix the issue, although some things like disabling ReBAR did lessen the frequency of it. I have already reported the bug to Asobo BTW.
what problem you are talking about, please?
this thread is about VRAM not being used in case when both GPUs are used concurrently for the same process, so VRAM (memory built in dGPU and dedicated for its exclusive use only) cannot be used, and shared video memory inside system RAM must be used instead. That’s no problem of MSFS, since it’s standard behavior for any such situation.
?? I don’t know what you’re talking about. The problem is that when there’s unused unallocated dedicated VRAM available, MSFS doesn’t use it but instead uses system RAM, causing extreme performance drops.This has nothing to do with the iGPU… Maybe I misunderstand your reply?
It has, since without using the iGPU it does not happen.
It does though, at least for me.
There is confusion from the start of this thread from @Takamura4240
There is no shared VRAM. It is the system RAM that is shared.
It appears that the reference is to the Task Manager screen that shows:
DGPU:
Dedicated GPU memory = 9.5/12.0 GB
Shared GPU memory = 2.8/23.9 GB
GPU Memory = 12.4/35.9 GB
-
I don’t understand the argument that FS2024 is using system RAM first.
If that is true then Dedicated GPU memory would be 0 GB.
And FS2024 would run very slower using the slower system RAM. -
The issue of the DGPU using 2.8 GB of Shared GPU memory with
2.5 GB of Dedicated GPU memory available.Task Manager displays the PCs total usage, not just the FS2024 usage.
In my PC:
-
FS2024 not running
Dedicated GPU memory = 2.4/24.0 GB
Shared GPU memory = 0.4/31.9 GB
GPU Memory = 2.8/55.9 GB -
FS2024 running
Dedicated GPU memory =19.4/24.0 GB
Shared GPU memory = 1.6/31.9 GB
GPU Memory = 21.0/55.9 GB (Dedicated + Shared)
The VRAM and RAM usage is the total of everything running in the PC.
That includes Windows and all apps. (MSI Afterburner) & (GPU-Z)
I don’t know what the system RAM used by the DGPU is for.
But, but it doesn’t mean that FS2024 is using RAM first and then VRAM.
1 Like
However, I don’t think this is the main reason for the performance issues in 2024, because 2020 sometimes allocates VRAM in the same way. I believe the real problem lies in 2024’s VRAM management, and perhaps, as the most popular post suggests, it’s actually a VRAM leak.
I don’t think I’ve had the issue in 2020 though, or at least it hasn’t been anything more than a temporary, small performance drop. But I’m planning on reinstalling 2020 so I’ll do some testing, but I’m pretty sure it’s a 2024 exclusive issue.
It has meanwhile proven that there is no VRAM leak in MSFS2024. Some had the idea during SU3 Beta, but it turned out not to be true.
Whatever the cause may be, what I can see as a player is that the dedicated VRAM usage decreases over time, which leads to my frame rate dropping. Asobo is expected to fix this issue in SU4, so all we can do is wait.
Decreasing VRAM usage over time is quite normal. VRAM is partly used as some kind auf cache and is freed if the objects have not been accessed a certain time. I observe this also. BUT: it is absolutely sure that this mechanism is not responsible for frame rate drops.
1 Like
Why do you think my frame rate dropped? I know about this VRAM mechanism, it frees up unused memory so that upcoming assets can fit, not to just keep reducing usage while clearly allocating a large amount of system memory as VRAM.
I think also, your frame rate drops due to the high usage of shared VRAM. Shared VRAM is in particular used by the iGPU. I observed it while connecting a monitor to the iGPU. There may be other reasons for this. I recommend to deactivate the iGPU if it is not used.
Let’s get back to basics for a bit. The task manager alone is not very valuable for diagnosing sim issues. Have you turned on the FPS display via the developer options in the sim, and monitored that for changes? Not only does it clearly state if you are CPU or GPU bottlenecked, but also shows other helpful processing stats.
There may be some other diagnostic steps depending on what the FPS display tells us. I think everyone has been too hyper focused on a single stat in the task manager and not considered the big picture.