The constant frame drops in novigrad usually happen near the marketplace or crowded areas so lets focus on getting those sorted first. If youre using an rtx card start by disabling ray tracing completely in cities since that helps with those nasty freezes especially around the fishmarket. Going into your nvidia control panel and setting up adaptive vsync with triple buffering makes a huge difference, and tweaking pre rendered frames to 1 helps smooth things out.

Maybe interesting the next gen update made some spots particularly tricky but theres a solid workaround grab the novigrad performance fix mod which cuts down npc density in trouble spots. For anyone running dlss switch to performance mode and use profile c through dlss swapper it really helps keep things stable. A neat trick is turning off the built in anti aliasing and using reshade with smaa instead gives you better looks without killing performance.

Its worth noting that even beast machines like an i7 with a 980 and 16gb ram still struggle hitting consistent 60fps in some spots. The engine just has some optimization quirks especially when gpu usage suddenly drops from 99% to 60% in crowded areas. Moving your installation to an ssd definitely helps with those random stutters you get while walking around the city but dont expect perfect performance its just how the engine handles dense urban areas.