---
title: "Fabulously Optimized in Prism Launcher — Install, RAM & Java Guide"
description: "How to install and run Fabulously Optimized (Modrinth & CurseForge) in Prism Launcher on Windows. Recommended RAM: 2 GB – 4 GB, Java: Java 21 (for 1.20.5+)."
canonical: https://prismlauncher.ink/modpacks/fabulously-optimized
updated: 2026-10-17
---

# Fabulously Optimized on Prism Launcher

Flagship Fabric performance and OptiFine-parity modpack offering massive FPS gains, shaders, connected textures, and controller support. Runs on Fabric (1.16.5 – 1.21.4) with 2 GB – 4 GB RAM and Java 21 (for 1.20.5+).

## Facts (2026-10-17)

- **Modpack:** Fabulously Optimized
- **Source Platform:** Modrinth & CurseForge
- **Mod Loader:** Fabric (1.16.5 – 1.21.4)
- **Recommended RAM:** 2 GB – 4 GB
- **Java Requirement:** Java 21 (for 1.20.5+)

## How to install Fabulously Optimized in Prism Launcher

Flagship Fabric performance and OptiFine-parity modpack offering massive FPS gains, shaders, connected textures, and controller support.

Click **Add Instance** on the Prism Launcher toolbar, choose **Modrinth** on the left sidebar, search for **Fabulously Optimized**, and click **OK**. Prism downloads the manifest and all mod JARs into an isolated instance folder.

## Recommended Java and memory settings on Windows

- **Java runtime:** Java 21 (for 1.20.5+). Configure this under [Java Settings](https://prismlauncher.ink/java) so the pack does not fail the startup compatibility check.
- **Memory allocation:** Set Maximum Memory (`-Xmx`) to **2 GB – 4 GB** under Edit Instance → Settings → Memory.
- **Need the app?** Grab the Windows installer or portable build from [/download](https://prismlauncher.ink/download).

## FAQ

### What if CurseForge blocks a few mods while installing Fabulously Optimized?

Prism Launcher opens the download pages for any blocked mods and watches your Windows `Downloads` folder automatically — click Download in your browser and Prism moves the files into place.

### How much RAM does Fabulously Optimized need?

Allocate 2 GB – 4 GB under Edit Instance → Settings → Memory, and ensure you are running 64-bit Java 21 (for 1.20.5+).

## Related

- [Prism Launcher Modpacks & Mod Downloader](https://prismlauncher.ink/modpacks)
- [How Prism Launcher's Automatic Downloads Watcher Handles Blocked CurseForge Mods](https://prismlauncher.ink/modpacks/fix-curseforge-blocked-mods-download-popup)
- [How to Allocate More RAM to Minecraft in Prism Launcher](https://prismlauncher.ink/java/how-to-allocate-more-ram-in-prism-launcher)
- [Prism Launcher Instance Management](https://prismlauncher.ink/instances)
- [Fabulously Optimized: FPS & Crash Fix Guide](https://prismlauncher.ink/modpacks/fabulously-optimized-fps-and-crash-fix)

## Download

Free and open source: [Download Prism Launcher](https://prismlauncher.ink/download)

Markdown mirror: https://prismlauncher.ink/modpacks/fabulously-optimized.md