While there is no single "189 fps boost mod" by that exact name, "189" typically refers to Minecraft version 1.8.9
Update your Java: Ensure you are using the latest version of 64-bit Java to allow the mod to use more RAM. 189 fps boost mod link
Here are the most reliable mods and clients to boost your FPS on version 1.8.9: Top FPS Boost Clients (All-in-One) While there is no single "189 fps boost
Unlock Your Device's Full Potential: A Comprehensive Guide to the 189 FPS Boost Mod Link avoiding thread stuttering on hyperthreaded CPUs.
The mod includes a batch script (.bat) that sets the game process to "High" or "Realtime" CPU priority and locks it to physical cores only, avoiding thread stuttering on hyperthreaded CPUs.