Hi.
I have noticed problem with FS 2, on my iMac when I am using external GPU (Blackmagic with Radeon RX 580) connected by thunderbolt 3. I have constant 60 FPS with Vsync, but every few seconds game freezes for about 1 second (no mather if I am flying over heavilly populated area or not). The same problem appears in FS 1, but other games, 3D applications or GPU benchmarks works correctly. When I am using internal RX 555 this problem does not appear but this card is a bit too weak for flying over some more populated areas. Have maybe anyone noticed similar problem.