Troubleshoot Low Frame Rates with UltraVanilla

Verify Prerequisites Are Installed

UltraVanilla requires both Iris Shaders and Sodium to function. If you're experiencing crashes or extreme lag, confirm both mods are installed and up to date. Missing either mod causes the shader pack to fail or run inefficiently.

Reduce Shader Intensity

Open Shader Options and systematically lower shadow distance, shadow resolution, and water reflection quality. Start by cutting these values in half, then test performance. Gradually increase them until you find a balance.

Check Render Distance

Shaders amplify the performance impact of render distance. If you're running at 32 chunks or higher, try reducing to 16 or 20 chunks. This dramatically improves frame rates while keeping nearby terrain detailed.

Disable Optional Features

Some UltraVanilla configurations allow disabling shadows or reflections entirely. If performance remains poor, try turning off one feature at a time to identify the culprit.

Monitor Frame Rate

Use F3 debug screen to watch your FPS while making changes. Small adjustments often yield significant improvements on potato PCs.