So simple - I turned off live traffic, and now my sim is running totally smooth. My conclusion is that I think every time the sim injects an updated position of a real world AI aircraft, there is a tiny stutter.
I hope they address this at some point as flying in empty skies is a little less enjoyable.
This has been my experience as well.
the traffic especially the live traffic creates a significant drop in fps and especially in the high resolution airports. The observation of the cameras stops being smooth and contains lags.
I don’t know guys how did you make it smooth, I have a feeling you fly GA airplanes. I am still flying with 25-30 fps on A320 and 787 even on medium settings, AA is bad, plenty of stutters. I was able to achieve 40-50 before the patch. I did turn off life traffic but it did not help me at all, and I have pretty good PC. This sim is clearly broken somewhere.
I’m running pretty smooth medium high. I turned off vsync and it stopped stuttering. Have you tried that?
I was flying the TBM whilst testing, around Oakland. I’ve got a Nvidea 2080 and an I7 9700 with 16GB RAM. Everything on Ultra except trees and grass, running in 1080p at a stable 40-45fps. All good except the stutters! Switching off the live traffic solved that - so very happy now. V sync doesn’t seem to make any difference on my PC, but worth a shout to try it. Good luck everyone.
Same here. I’m running 9900, 2080 and with live traffic off I’m not just stutter free but my frames are more fluid. Also live traffic is a mess, you have random planes popping up and planes that decide to stop on the runway and not move. It’s a work in progress.
Did all that, sitting at LAX on the Rwy in A320, fps 25-30 good weather.
9-9900K, GeForce RTX 2080 Ti 11GB, G.SKILL TridentZ 32GB
Are you guys turning off REAL TRAFFIC under the traffic sections in options or under the DATA setting in options?
This is an odd setting because I’ve seen some people have good luck with turning it off, while it didn’t change anything for others. I’m in the latter crowd. Now, AI traffic, on the other hand, will cause a lot of stuttering for me, or at least it did before I upgraded to an i7-10700K. (Finished the build at 2am this morning, then went to bed.) I may have to try the AI traffic again. 
Just an addition to this - I’ve deleted all the custom liveries from my Community folder - huge decrease in stutters and a large frame rate gain. My conclusion for that is each “AI” aircraft being rendered is a “full” aircraft, rather than a “light”, for want of a better word, AI aircraft. I could be totally wrong but thought I’d mention it. Good luck! Hopefully the MS liveries for traffic if they ever come out will be less GPU/CPU intensive.
It would be interesting to know if this “traffic” issue is a hardware bottleneck (is it CPU or GPU causing the stutters) or is it a coding issue/bug and upgrading HW will not help.
It FEELS like whenever anything live is being injected into the sim, be it live weather, live traffic, it causes stutters. I’ve turned all that off, and deleted the community liveries and I’m almost - not quite - stutter free. Personally I would think it is a coding bug.
Live traffic and live weather is created “on fly”, means CPU load generated through add. downloads plus injecting in the sim. Maybe you can watch your CPU and network activity with and without live stuff.
I’m afraid that it might be poor code optimization as well. Although I actually hope it’s a GPU bottleneck as I plan to get a new 3080 and will be disappointed if I still can’t enable live effects at 4K after that.
If it’s a coding issue, who knows how long we might have to wait before they patch it.
all smooth here if live traffic and live weather off, so my gut feeling is not GPU related. Hope not as this is a brand new pc with a 2080 nvidea card!
Anyway I’ve decided to stick with enjoying some VFR and enjoying the visuals until the atc and live weather issues are fixed!
Turn off all traffic for Better FPS too.
The legacy sims were exactly the same. When ai traffic is added or removed it caused a stutter. This is nothing worse.
I didn’t find AI traffic that bad in FSX. It did cause FPS drops in really dense areas but im not sure if thats just because I was at CYYZ or the amount of AI… Either way it didn’t stutter that bad, mostly just framerate drop which I dont find as annoying.
I’m really talking about the micro-stutters that are continual, rather than the pauses as something loads in. But all valid comments, my FPS is pretty pegged at 40-45 with with everything on ultra apart from trees and grass, but the stutters don’t cause frame rate drop - it can be stuttering at 45fps. All a bit odd! Anyway, thanks everyone for the comments.