I had similar issues with my 4070 Super running 4k with high to Ultra settings. Just awful stuttering with Frame Gen turned on, but I would turn it off and still manage decent fps. I’m running it with a 12400, so I assumed this was some sort of CPU related bottlenecking…but after some research on sites unrelated to MSFS< it was pointed out that this issue is occurring when maxing out the VRAM usage. Sure enough, this is exactly what was happening.
Then I had great success using the recommended setting in the new Nvidia App, which lowered a couple of the settings (but actually increased my OLOD and TLOD surprisingly) and lowered my DLSS mode to Balanced. This all did the trick and now FG is working beautifully. I’m getting 30-40 fps in the PMDG at big 3rd party airports, and it still looks beautiful. Very pleased with where it’s at, and if SU15 is as smooth as people are saying, well, I just might be flying a lot more than all of this tinkering.
For the first time, I just used DLSS Swapper and added 3.5.10 to the sim… hoping I can see better results on my 4090 with Frame Generation (native FG in this sim is bugged, ever since SU14 and continues to be in SU15 beta – random times, my screen will start “shaking” and stuttering to the point I have to turn FG back off, then back on in the menu settings).
UPDATE: Had 2 flights since updating via DLSS Swapper and my performance was amazing. Top notch. Had a couple of stutters here or there, but stayed in the 70s on 4k/ULTRA. Woo hoo!
With a 3 monitors setup, total resolution of 5760x1080. I don’t have any stutters at all. Airports JFK, London Heathrow are as smooth as butter.
Using A320, All settings on high, live traffic and weather, DLSS 3 Quality + FG.
The RTX 4070 Super together with AMD Ryzen 7 5800X3D create enough performance for a good overall experience.