Yes, SMP + RWC also takes some performance. Mostly drops I have are in central europe regions, Big urban areas with many objects have a bad influence when you cross over, even in cruise altitude and it drops dramatically if many clouds are covered. I see this also when I set the default clouds, but fps are slightly better compared with SMP.
Tolix, in EDFF I have appr. between 12 and 28fps (goes up and down) activate world traffic with lot of AI animation. GPU and CPU are utilized between 40 to 60 degree. I think it is not a problem of graphic-card and processor but memory capacity and bus bandwith..
Jack