Frame generation in MSFS - the good and the bad

[Cpt_Piett 4,670]

The introduction of frame generation (FG) has been a game-changer for many RTX40-series owners. However, the AI-tech behind FG is not infallible. 

FG-related artifacts are an inherent problem with the frame generation AI technology (DLSS3) but can be avoided.

The AI-tech behind FG basically inserts an AI-generated image in between two native images:

The problem is that the AI tech sometimes fails to render the AI-image properly (causing artifacts). Factors that increase the chance of seeing these artifacts:

• native FPS is too low - I find that at least 30 non-FG FPS is needed for FG to work properly
• very fast panning
• very fast-moving objects
• very fast-moving numbers e.g. on speed-tapes

I rarely see these artifacts. In fact the last time I can remember seeing them was on the dev mode FPS overlay where the numbers were changing extremely quickly:

For some in-depth information about how FG works, and how it sometimes can create artifacts, I highly recommend this detailed analysis (they also talk about MSFS): https://youtu.be/92ZqYaPXxas?si=nk5bLaJPzUvg6gH4

Some examples of fast-moving objects where the AI tech fails to render accurate AI-frames (perhaps more relevant to more fast-paced games): 

Clearly, some people are much more sensitive to these artifacts than others. I've made many videos lately, and honestly haven't seen much of these artifacts, if at all. 

When considering getting a RTX40-series card, I highly recommend pairing it with a decent CPU. I have a 12900KF which IMO is working fine. Another thing: A 4090 is not needed unless you want the absolute best (and can afford it). 

Perhaps the biggest advantage with a 4090 is 24GB of VRAM. I've seen total VRAM usage up to 23GB. But that's an extreme example, usually it's much lower than that. In one of the most demanding locations in the sim, VRAM was about 15-16GB:

I've been flight simming for more than 25 years. I've custom-built PC's for just as long. Performance has always been a problem. The most game-changing upgrade I've ever done was getting the 4090. 

Comments? Is it worth getting a RTX40-series card? Are people distracted by the artifacts?

Hopefully this thread will generate some discussion as FG seems to be a very hot topic.

Edited March 27 by Cpt_Piett

[Cpt_Piett 4,670]

Double post, sorry.

Edited March 27 by Cpt_Piett

[btacon 1,806]

Cpt, You're a pretty sharp individual and your insight is always appreciated. 
-B

[Noel 4,503]

1 hour ago, Cpt_Piett said:

Performance has always been a problem. The most game-changing upgrade I've ever done was getting the 4090. 

Comments? Is it worth getting a RTX40-series card? Are people distracted by the artifacts?

You already fully appreciate my POV on this topic. I will add this huge issue for me which, along w/ artifacts all of which I experience despite an FG rate of 70 or even 80 (it's all my CPU can deliver w/ my config as it is) it's the big frame rate drop when moving the mouse to my 2nd display, which in my case is nearly constant) and then the often big judder when the mouse activates back on the MSFS main display.   These things have killed FG for me and I'm glad to be rid of it.  But the 4090 w/ its processing increase over the 3080Ti and its VRAM has totally improved my sim experience, and that mostly from the high VRAM which lets me set Render Scaling to 160% on my native 3440x display.  This has not only sharpened everything to the max w/o a hint of artifact but the 2-screen problem disappears as well w/ FG off, especially the judder issue which kills immersion repeatedly for me.  Another big plus is the high render scaling causes the cloud edge voxel grid to shrink accordingly and can't really see it any longer. 

I think it's possible a new CPU will improve the artifacts I get, but doubtful it will do much for the 2-screen issue.  If it does obliterate artifacts I can deal w/ the 2-screen issue by avoiding looking at it before moving the mouse cursor to the main screen, i.e. keep my gaze on the 2nd display until after clicking on the main.

So yes the 4090 was my best move at this point in time.  I previously assumed a new CPU was what was needed, and it will be nice to have soonish but really it's the VRAM and Render Scaling that comes w/ 4090 that wins the day here.  

Edited March 27 by Noel

[AnkH 2,267]

To be honest, and of course it is slightly in defense of my purchase, but with Frame Generation, the 4080 does almost an equally good job compared to the 4090, simply because baseline FPS are mostly limited by the CPU anyway. Only the relatively small VRAM speaks against the 4080. Besides that, I bet I get more FPS per Dollar 🤣

[Cpt_Piett 4,670]

39 minutes ago, Noel said:

You already fully appreciate my POV on this topic

I do, and although our experience with FG differs, I still appreciate your opinions. As long as your feelings on this matter are clear 😉

Jokes aside, I’m starting to think that your CPU is not the problem at all. You’re saying you’re getting “FG rate of 70 or even 80”, which I think should be above the threshold for FG to work properly. I’ve been doing a lot of testing (with AutoFPS) lately, and I’m fine with an RTSS-lock at 65 FPS.

I wasn’t aware that you’re using a multi-monitor setup. Could this be the cause of your FG-woes? Perhaps “the judder issue” is not the artifacts I described in the opening post. Have you tested with single monitor only? Does that make the judder go away?

34 minutes ago, AnkH said:

To be honest, and of course it is slightly in defense of my purchase, but with Frame Generation, the 4080 does almost an equally good job compared to the 4090, simply because baseline FPS are mostly limited by the CPU anyway. Only the relatively small VRAM speaks against the 4080. Besides that, I bet I get more FPS per Dollar 🤣

I don’t doubt this for a second. And I fully agree with the point you’re making re: CPU limitation. 

I was most likely suffering from grandiose delusions when I splurged on the 4090. Which means I should be acquitted, right? 😉

Edited March 27 by Cpt_Piett

[Noel 4,503]

The main artifacts associated with FG for me are strobing out the mostly side view at certain tarmacs, like FB's KDEN heading east out of a gate, like B45, in dawn light, when panning or moving.  It's really not good at all, but limited yes to certain lighting conditions.  Now add to that glass cockpit lines/symbols whenever you pan no matter what the speed:  they shimmer or are just unstable for lack of a better descriptor.   Compared to rock solid stable imagery, they're not good.  I've mentioned the 2-screen issue many times.  Doesn't matter if the 2nd screen is connected to the same GPU,. or the iGPU on the mainboard.  If I click something on my 2nd display, IOW make it active, then MSFS frame rate drops by maybe 40%.  That's not so bad but when returning to the main screen the judder is no good.  I'm spoiled by perfection in imagery.  

The CPU limits greatly how much traffic I can use w/ FSLTL, what I can set TLOD to, and also would let me set my base FPS lock from 36 to say 46 or so and retain all the wonderment of my current config.

[Cpt_Piett 4,670]

8 minutes ago, Noel said:

The CPU limits greatly how much traffic I can use w/ FSLTL, what I can set TLOD to, and also would let me set my base FPS lock from 36 to say 46 or so and retain all the wonderment of my current config.

Fair point. I’ve been able to run pretty high TLODs with my 12900. Not really necessary with airliners, but I do a lot of GA/scenic flights too. I use FSLTL w/ max 30 IFR, max 30 parked AI. On approach to EGLL etc I’m happy with TLOD 50 or 100 below 1000ft. I aim for FG-FPS 65+.

Not planning on a CPU-upgrade anytime soon. It has served me very well since I got it summer of ‘22. Hopefully I’ll be able to keep the 4090 for many years to come.

Edited March 27 by Cpt_Piett

[Vali 83]

I use my Ryzen 5900X between 20-40% (but no AI traffic and Core0 is excluded from the Affinity Mask) and the 3080Ti FTW3 around 60-85% with decent settings, DX12, FG, DLSS Quality. As you mentioned, the RTX4090 has the advantage of the VRAM and it alows higher settings (texture resolution and so on), 12GB is marginal sometimes for me. On my case I reach 80fps (FG and limited to 80 in NVCP) which is fine (4K but clearly not settings at Ultra or High). 

With RTX 4090 I think higher TLODs can be achieved also 😄

FG is not artifacts free for sure (depends as you mentioned by the achieveable minimum fps when there is not so much to interpolate, also panning is usually affected and so on), DX12 is still beta.

Edited March 27 by Vali

[Fiorentoni 4,235]

Every once in a while I'm quite happy of having a 1080ti and not having to think about that modern technological stuff 😄

[Cpt_Piett 4,670]

42 minutes ago, Fiorentoni said:

Every once in a while I'm quite happy of having a 1080ti and not having to think about that modern technological stuff 😄

I'll be the first one to admit that it can be a curse. Just fell down into another rabbit hole called DLSS tweaks and now MSFS has gone completely black! 😅

Edited March 27 by Cpt_Piett

[Luis Hernandez 570]

6 hours ago, Cpt_Piett said:

Comments? Is it worth getting a RTX40-series card?

I'll wait until knowing what does MSFS 2024 require. Going to a 4060 Ti from my 3060 Ti is too small of an upgrade, and going 4070 would be overkill for a 1080p monitor. All I know is that my 5600X needs to be beefed up.

[Cpt_Piett 4,670]

26 minutes ago, Luis Hernandez said:

I'll wait until knowing what does MSFS 2024 require. Going to a 4060 Ti from my 3060 Ti is too small of an upgrade, and going 4070 would be overkill for a 1080p monitor. All I know is that my 5600X needs to be beefed up.

I made a pretty big leap in 2022 - 1080Ti to 4090. Like you say it's probably better to have a higher resolution to fully be able to appreciate the eye candy that RTX40-series brings.

[z06z33 763]

It works well for steam gauge planes but I have issues with glass cockpits 

[MrBitstFlyer 3,875]

7 hours ago, Cpt_Piett said:

native FPS is too low - I find that at least 30 non-FG FPS is needed for FG to work properly

Interesting you say this, and I guess everything is system specific, but I have completely smooth frame times at 50 FG FPS.  Native that's 25fps, but absolutely smooth performance.  I can run at 60 FG fps,  but AutoFPS shows I am stuck around 100 TLOD.  Setting 50 FG FPS allows extra resource for more TLOD.  Interestingly, I can set 40 FG FPS (for more resources for TLOD) and still get completely smooth frame times.  Perhaps MSFS is well suited to low FG FPS as I haven't tried in any other games.

A new PC or upgrade is not near, but I'm still happy with my PC for now. Absolutely with Noel on this - smooth frame times equal a smooth and flyable sim with little difference between 40 or 60 FG FPS visually.