When Are You “Out” of VRAM (MSFS)

[regis9 4,119]

Hello, I’ve been monitoring VRAM usage as a possible source of stutters in large cities in MSFS and I’m wondering how to figure out when I’m “out” of VRAM versus just getting by.  

An example would be last night in the Fenix I was descending over Vancouver heading for YYJ and when I looked I had about 800mb of VRAM left.  What I’m unsure of is if that means I was just getting close to being out (ie was that 800 a true buffer?) or would I have been in a range where the card (or MSFS?) was restricting my VRAM usage to keep it from getting to zero available…I’m not really sure how this works.  Once I got to Victoria I had about 3gb available.

One thing is for sure, my RTX4080‘s 16GB of VRAM is not providing the VRAM overhead I expected.

[alepro21 160]

Are you using DX12?

I assume so, since you probably want to make use of the “Frame Generation” feature unique to 40xx cards, but asking just in case. Dx12 is known to use more VRAM and (according to my limited knowledge) the VRAM management is up the GPU, and what I have experienced with my 4070Ti (which only has 12 GB of VRAM) is that Dx12 seems to be more VRAM hungry. 

Edited August 17, 2023 by alepro21

[David_CSA 36]

I have basically the same question, please.

And I don't want to steal this discussion, but allow me to ask perhaps even more basic question:

How does lack of VRAM demonstrate itself? What shall I look for?

Some people mention stutters. I believe that but stutters can be caused by multiple things, right?

I believe VRAM is important, but failed to recognize the issue. I have just 8GB and took other precautions to eliminate stutters (method @Noel). I do admit I fly just default scenery at 1440p.

Some people here are warning against 12GB and some mention surprisingly high utilisation with 16GB.... I remember the initial reviews of msfs 2020 saying all graphical memory is always used.

But what's the real problem with the lack of VRAM??

 

Edited August 17, 2023 by David_CSA

[alepro21 160]

It’s not just stutters but can also be a reduction in frame rate. A great way to check for this issue is to pan the camera around 360 degrees horizontally and then do another 360 degree rotation. If this is not fluid then VRAM might be an issue. Of course there might also be a complex object in view, so I would also look at the VRAM amount to ensure that stutters are related to the stutters.  

Edited August 17, 2023 by alepro21

[regis9 4,119]

Thanks, yes I’m in DX12 to make use of frame generation.

The stutters when panning is an excellent example/test of bumping up against VRAM limits.

Ugh, probably should have waited for 4090s to come in stock and bought one of those.

[RJC68 831]

17 hours ago, regis9 said:

Thanks, yes I’m in DX12 to make use of frame generation.

The stutters when panning is an excellent example/test of bumping up against VRAM limits.

Ugh, probably should have waited for 4090s to come in stock and bought one of those.

It was my understanding MSFS will just utilize whatever VRAM you have,

My recent cards were 1080TI, 3080TI,3090 & 4090 and I never ever came close to using all the VRAM on any of them. The highest I have seen m VRAM usage get too on my 4090 is around 14GB. I am using DX12 with FG

Are you using a ton of addon scenery where this happens or does it happen on every flight no matter what aircraft you are in or where you are in the world? If you can give an example of an airport/aircraft situation I can have a look. I do not have a lot of payware scenery but do have FlyTampa CYYZ

I typically fly the Fenix or PMDG with everything on Ultra and never see this issue, it is weird you are with a 4080

Edited August 18, 2023 by RJC68

[G-RFRY 1,765]

Desktop GPU`s no longer important more profits elsewhere.

Nvidia Makes 1,000% Profit on H100 GPUs: Report | Tom's Hardware (tomshardware.com)

With basic materials getting more expensive better to use them for the most profitable hardware.

[regis9 4,119]

9 hours ago, RJC68 said:

Are you using a ton of addon scenery where this happens or does it happen on every flight no matter what aircraft you are in or where you are in the world? If you can give an example of an airport/aircraft situation I can have a look. I do not have a lot of payware scenery but do have FlyTampa CYYZ

Thanks, if definitely doesn’t happen everywhere, a GA flight in the middle of nowhere will be fine.  It’s airliners at payware airports with lots of AI running.  I feel like photogrammetry maybe is a factor too?  The example that made me post was descending over Vancouver into Victoria in the Fenix A320…I was still probably 18,000 feet up over Vancouver running a very low Terrain LOD (I think 50) and things started getting stuttery.  I have FsimStudios CYVR though I’m not sure how much if an impact it would have from that altitude.

Flying an airliner out of FlyTampa CYYZ is certainly a challenging situation that will see very little VRAM headroom available for me.

I see that the new AIG models have had a lot of work done to reduce resource draws, I’ll be curious to see how some of these flights go with new AI traffic models.

Edited August 18, 2023 by regis9

[G-RFRY 1,765]

Nvidia vs AMD vs Intel: Last 12 Months of GPUs Are Disappointing | Tom's Hardware (tomshardware.com)

Not a good time for GPU`s.

[Ixoye 1,881]

As I suspected, 16GB is not enough either, I have a 4070Ti 12GB and have given up on DX-12 and FG.