I’ve had very similar issues over different times even with my very old system (i7700k, GTX1080, 32gb RAM…)
I’ve stuck with my old system because when it runs great, it’s great locked at 30fps. I’m also trying to hold out spending money until MSFS24 or until I really want/need to. Landing and deparing with FSLTL traffic, using FS Realistic, GSX, FSUIPC, TrackIR and other items running… it’s understandable on my old system to have issues and low fps at times, but I’ve also been getting 100% CPU spikes over the last week.
I’ve also tried running Task Manager, killing programs to see if they help or hurt the CPU, etc. I have the same results as that I ONLY see MSFS spiking… whether apps are running or if I’m using a bare-bones sim, high or super low LOD’s, etc.
Brings me to think that it has more to do with the state of the servers for streaming the data over to your PC; that MSFS gets packets of data and it fluctuates which causes your CPU to render all that information… then it doesn it again… and again.
Your severely superior system specs shoudn’t have the stutters and CPU spikes like my very old system does. Again, brings me to believe that it has more to do with the actual MSFS side of things… server or data.
Again, I have weeks where I have absolutely NO CPU spikes, and then like this weekend, I had them all day Sunday.
Just my $0.02
-GolfKilo
P.S. this was also meant to be aimed at the system of the OP of this thread @theolm98