Lower resolution
Use fullscreen or borderless windowed mode
Set graphics quality to low
Turn off background parallax
Disable frame skip if it causes stutter, or enable it if needed
Close other programs before launching the game
Disable overlays like Discord, Steam, GeForce Experience, and Xbox Game Bar
Update GPU drivers
Verify Terraria, tModLoader, and mod files
Remove unused mods
Disable resource-heavy mods
Lower screen shake and visual effects in mod settings if available
Reduce lighting quality
Turn off blood and gore
Turn off particles if the mod or config allows it
Limit FPS to a stable value
Use a performance-focused texture pack
Clear excess world clutter and dropped items
Avoid large numbers of minions, sentries, and projectiles
Reduce summon count during boss fights
Fight in a simpler arena with fewer background objects
Use a smaller arena with less placed furniture and decorations
Turn off music visualizers or external audio effects
Allocate more RAM to tModLoader if needed
Reinstall tModLoader if performance is corrupted
Use the latest stable version of Calamity and Infernum
Check for mod conflicts
Disable recording software while playing
Lower Terraria zoom level
Play in single-player instead of multiplayer if possible
Restart the game before long boss sessions
Use performance mode in Windows power settings
Set Terraria to high priority in Task Manager
Disable cloud sync while playing
Keep the game on an SSD
Reduce resolution scaling on your monitor if supported
Turn off shader mods
Avoid spawning extra NPCs near the boss arena