Why does my Splinter Cell Remake performance drop?

Stealth phases in Splinter Cell Remake were stuttering due to high temps. Adding case fans only made it noisier. I used GamePP to raise the 75C target from 1500 to 1700 RPM. AIDA64 now shows 72-75C temps, and HWiNFO confirms 1700-1900 RPM, proving the cooling is efficient and the performance dips are gone.