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Minecraft 1.20.1 Forge — Instance & Java Setup Guide

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Routeprism launcher mc 1 20 1 forge setup and java guideminecraft 1.20.1 forge instance & java setup guidehow to set up minecraft 1.20.1 forge prism launcher

Blueprint for creating a clean instance with the exact required Java runtime and heap RAM on Minecraft 1.20.1 Forge using Java 17 (64-bit) and 6144–8192 MiB RAM in Prism Launcher.

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Minecraft & Loader
Minecraft 1.20.1 Forge
Workflow Task
Instance & Java Setup Guide
Required Java
Java 17 (64-bit)
Recommended RAM
6144–8192 MiB
Loader Stack
Minecraft Forge 47.x

Blueprint: Minecraft 1.20.1 Forge × Instance & Java Setup Guide

This route configures **Minecraft 1.20.1 Forge** inside Prism Launcher for creating a clean instance with the exact required Java runtime and heap RAM. Start by creating an instance with **Minecraft Forge 47.x** in the Version tab and assigning **Java 17 (64-bit)** under Java Settings.

Set Maximum Memory (`-Xmx`) to **6144–8192 MiB** so chunk loading, mods, and shaders run without garbage-collection pauses.

Prism Launcher screenshot showing the instance management user-interface
Each instance has its own version, mods, settings and worlds.

Step-by-step checklist on Windows

  1. Install or update Prism Launcher from /download and click **Add Instance**.
  2. Select the Minecraft version and install **Minecraft Forge 47.x**, then verify **Java 17 (64-bit)** is selected in Settings → Java.
  3. Use **Edit Instance** → **Mods** → **Download mods** to pull verified jars from Modrinth and CurseForge.

Frequently asked questions

Which Java version do I need for Minecraft 1.20.1 Forge?

Use **Java 17 (64-bit)** with **6144–8192 MiB** allocated under Edit Instance → Settings → Memory.

Can I export this instance to share with friends?

Yes. Right-click the instance and click **Export** to save a `.mrpack` or Prism ZIP archive.

Get Prism Launcher

Windows, macOS & Linux

Free and open source. Sign in with the Microsoft account that owns Minecraft, then create your first instance.

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Prism Launcher on Windows showing several modpacks and instances