Why does The Witcher: Remake flicker during combat scenes?

While tracking monsters in the deep jungle of The Witcher, I noticed slight screen flickers and frame drops whenever casting wide-area signs, which totally broke the immersion. I first tried disabling all power-saving options in the BIOS, but while temperatures rose by 5℃, the voltage fluctuations persisted, leaving me puzzled. I then used the GamePP Power Plan Switcher to lock the system in Ultimate Performance mode and adjusted core voltage priority via the Resource Scheduler. Finally, voltage fluctuations converged to within 0.1V per HWInfo, and frame times stabilized at 16-20ms per RTSS, while fans hit 800-1100 RPM per GamePP.