Performance & FPS

Trying to find out why a single 4K car texture pack causes my FPS to drop from 120 → 60 on a 4090. Not a VRAM problem (16GB used / 24GB). Not stream memory either (extender configured). Profiled with NSight: looks like the bottleneck is ...

Smooth fps but a noticeable hitch every ~30 seconds while driving. Only when mods are enabled; vanilla runs butter smooth. Strace-style profiling reveals that it's some kind of background streaming spike. Anyone else seeing this with a l...