Why does Banishers: Ghosts of New Eden lag during combat?

While exploring the forests of New Eden, I noticed that whenever I entered complex combat, the frame rate would plummet from 75 to 42 FPS, totally breaking my immersion. I first tried disabling Turbo Boost in the BIOS; while temperatures dropped, overall performance lost nearly 20%, leaving me confused by such an inefficient approach. I then accessed the GamePP Fan Curve Configuration Panel, moved the speed threshold from 65℃ to 50℃, and applied a more aggressive linear curve. Finally, CPU frequency stabilized at 4.4GHz per CPU-Z, temps stayed at 66-72℃ per HWMonitor, and FPS converged to 68-74 per GamePP FPS Counter, with peaks at 88-92℃ per AIDA64 and fans at 1200-1400RPM.