thanks for the fast answer.
My class is Destroyer, it happens everywhere. I got on the map normally 80 FPS and it decreased to 17. Doesn't matter if i stand there alone or with 20 people.
My FPS drops down to 10 if i engage into combat. In raids my FPS are dropping to 2~5. My game totally freezes and i'm unable to do something until the boss is finished.
My equipment is:
Sapphire rx 570 (8GB - retail)
intel core i5 4690
Windows 10 - 64 Bit Version
Ram - 24 GB
(i hope it's enough information)