Why does Splinter Cell Remake stutter in shadow areas?

I felt absolute despair during stealth missions; every time I shifted perspective into complex lighting, abrupt micro-stutters destroyed the tension. I tried increasing the system page file to 16GB, but while FPS rose slightly, the frequency of frame drops actually increased, leaving me confused. I then used the GamePP Resource Scheduler to set the game process priority from Normal to Realtime. Frame generation time converged to 11-14ms per GamePP Frame Time Analyzer, memory usage sat at 7.2-7.8GB via AIDA64, and temps stayed 42-48℃ per HWMonitor.