Why do my magic spells flicker like a broken projector in Avowed?

I noticed my magic spells flickering terribly in Avowed, looking like a broken projector. I tried increasing virtual memory, which made it worse by dropping my frame rate to 30 FPS per in-game tests. GamePP revealed background data sync was hogging bandwidth, keeping utilization at 85%-92%. I used the GamePP Resource Scheduler to set that service to lowest priority. The average frame rate jumped from 45 FPS to 60 FPS, and bandwidth utilization stabilized at 70%-75%, making the magic effects look crisp and clean.