I tried to turn off Hardware Accelerated GPU scheduling as mentioned here (https://www.youtube-nocookie.com/embed/1wyGrn2xV0k MSFS2024 VRAM issue got fixed.
I have 4080 GPU and the VRAM keeps around 10G and FPS keeps at 30-40 at 4K.
Perhaps not completely related, I have hags on, using taa and fsr3 on a 4070ti super 16gb vram and getting the best performance ever, not graphics warning and normal looking vram usage
2 Likes
How much RAM do folks have? My understanding of HAGS is that it makes RAM available for graphics processing, in effect momentarily extending VRAM albeit at a cost of some lag, should that extra memory be needed by the GPU at that moment. To discuss HAGS on/off without considering available RAM might be missing out on a key PC spec? Just a thought. Cheers!
I have 32gb
1 Like
I think it’s the other way around. It allows other processes to also use the VRAM on the GPU for other things (since VRAM is generally faster). This probably explains why VRAM use can increase with HAGS.
2 Likes
Do you think we should be using resizable bar too?
I tried this and for me it doesn’t make any difference (Nvidia 3070)
(I still have VRAM issues with HAGS off, ReBAR on, Raytraced shadows off, 1980p screen size, 100 LOD, 100 OLOD, settings on medium or high)
Interesting, I have not come across this yet. Where can I read more about that?
64 GB of ram and 16 GB of VRAM.
Alternative: I’ve kept HAGS ON but set Resizable Bar (in Bios) to OFF with the benefit of not seeing the MSFS alert window anymore 
2 Likes
ReBar was mentioned in another thread that it causes increased Vram usage. As an extra if you only use fsr3 for frame generation you can also turn hags off as it’s not needed, that will free up even more Vram.
Obviously if you use Nvidia FG then it needs to be kept on.
2 Likes
I am on 4060 8G, 16 GB RAM and HAGS ON simply kills my sim (DXGI_ERROR_DEVICE_HANG) if I select a more or less complex airliner
This article explains that “without this feature, the CPU can only get data to process from the GPU’s memory in 256MB chunks.”
It goes on to say “that’s where SAM (AMD’s version) or Resizable BAR (Nvidia’s) comes into the picture, literally. With this feature activated, the CPU can access the entire “frame buffer” (another name for the GPU’s memory), which means it can quickly find and process the data it needs.”
So, it doesn’t “use” VRAM as far as I can tell from the article.
Except it does.
The sim will use 1-2GB less VRAM and have 1-2 GB more VRAM available as a limit in-sim with Rebar OFF.
I upgraded from my 4070 Super to a 9070 XT hoping that the extra VRAM would fix all my airliner stuttering issues and I was floored to find that I couldn’t increase resolution to High at any large airport because I would hit the vram limit and the sim would start stuttering. I found the thread that recommended turning it off and it was night and day.
I haven’t had to care about rebar in any other game, so probably in this one, something is broken. Either the sim or driver-related, but both nvidia and amd users are reporting benefits to turning it off.
4 Likes
That’s exactly all the experiences I share too. So yeah, in theory the reBAR shouldn’t cause a higher VRAM use but something does cause that…
In every scenario where vRAM gets overspilled, my FPS drop. reBAR causes the same effect and the VRAM is utilized by 1-2GB more. Something just seems to work differently when it’s on.
For me (gpu amd 9070xt), ReBar OFF in the bios has a measurable positive effect: more fluidity and less stuttering.
In any case, the vast majority of the time, MSFS 2024 uses little more than 8 to 12G of the 16G of vram of the graphics card in ultra settings at 1440p… so I am well under the limit with ReBar OFF.
64GB RAM
24GB VRAM
HAGS off
ReBAR on
4K, HDR on, mostly Ultra/High.
DLSS 4 Quality
Live weather, FSLTL
I don’t think I’ve ever seen more than 14GB VRAM usage. Usually 9-12.
I’m currently in the AzurPoly Jaguar at a ramp in KSEZ. VRAM is 11.14GB. 55 FPS (native.)
Render native and you’ll see a few gigs extra used as you’ll render at 4k and not 1440p.
And then run the Fenix at their dallas default airport or an a350 (without cabin) at a large airport. With rebar on, on 16gigs vram you’d have 12.something GB available and hit that limit quickly. FSR4 takes me down to under 11 with traffic at large airports and Fenix
With Rebar off you get 13.6 or 14.something available and the sim doesn’t really jump over 12 unless pushed hard.
How are you using FSR4 in MSFS?
Optiscaler. Set it once, it just works.
Turning HAGS off disable Nvida DLSS frame gen. How are you all getting around that? Using AMD cards/frame gen or no frame gen at all, maybe?