"Only the main thread is very high" hehe. Sadly thats more or less the depending factor for most of us. Surely one can bring many GPUs to max too in one or other way but mainthread its always the thing thats bottlenecks most of us.
Meaning, if you are anyway already near limit of the mainthread, what is very easy by setting Terrain LOD higher, or fly in busy areas, have traffic plugiins hacking on it etcetc, anything on top can cause this. And if that is maxed the other components cant get enough info and are idling, more or less. Many ways to go into this state in MSFS.
You would really have to make sure that you didnt change anything else.
Also, of course im not sure if you have but the suggestion from Asobo to install updates with a renamed community folder, start sim like that first etc is not a bad tip.
Whenever i run into these problems, ie update gives less fps, i do a full clean up. Scenery indexes, rolling cache deletion, rename community folder and all those things. In basically every time that fixes any of those issues.
But of course there can be many things. I think ive seen another topic here about that, maybe you find some info there. It shoulndt be very much further from first few pages.
But, that was for SU14 ^^ I think you see where im going with this.
