Perf Boost is a Fabric mod for Minecraft 1.21.10 that adds a toggleable performance HUD (FPS, RAM, CPU, ping, etc.) and an optional performance mode.
What this mod does
Perf Boost adds a stats HUD in the top-right (toggle with P) showing FPS, frame time, RAM usage, entity and chunk counts, ping in multiplayer, and CPU usage/temperature when available. It also adds performance mode (toggle with O): when enabled, the mod temporarily lowers your graphics settings to improve FPS, and restores them when you turn it off.
What performance mode changes
When you turn performance mode on, the mod temporarily applies:
When you turn it off, your previous settings are restored. Nothing is written to your options file; it only affects the current session.
Why use it
Performance HUD (press P to toggle)

Keybinds in Settings

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