Dragon's Prophet can't be compared to a well optimized game as it is using 12 year old middleware for the UI engine, which is where the majority of your FPS loss occurs. Due to how packed Laedis is, and how large that map is, you will experience the most FPS drop in that game. I have literally been in Laedis with on a computer with 2x Intel i9 CPU, and 2x GTX Titans and not been able to get a decent FPS.
We are working on trying to update the UI engine, but it is very complicated and has been problematic so far. Once we can get that completed FPS will be more in line with modern games.