Installing MultiMC & MC Eternal

Discussion in 'Guides & Tutorials' started by darksaid98, May 15, 2021.

  1. darksaid98

    darksaid98 Community Leader Staff Member Community Leader

    Jul 27, 2018


    Soon Athyrium will be opening a modded Survival Minecraft server. In the interest of giving every member an optimal, lag-free experience I have written you these guides.


    • I only have 8GB's of RAM, can I run this? Yes. However, I do highly recommend using a custom JVM for the reasons outlined here.

    • I only have 4GB's of RAM, can I run this? No. However, you can download more RAM here.

    • What is the mod pack we're running called? MC Eternal Lite.

    • Do I need to do everything this way to play on the server? No, this is just the cleanest and most optimal way of modding Minecraft.

    • Why are these guides so long? They really aren't. They just assume mental deficiency in the reader.

    • Hurr, Durr! Why MultiMC!? Is there any bloatware-free, open-source program that's better? Get with the times pleb.


    Launcher Installation


    To launch and install the mod pack I've chosen MultiMC 5 as my launcher of choice. This is because MultiMC is lightweight, simple yet not lacking in advanced features but most importantly. MultiMC does not come bundled with bloatware such as Overwolf or Twitch as Curse does/has done. Your pc will thank you.


    1. Go to the MultiMC website and the downloads page.

    2. Scroll down until you see the section called 'Download & Install the development version'.

    3. Click and download the Windows development version of MultiMC.

    4. Store the '.zip' file anywhere on your computer.

    5. Unzip and extract the contents of ''. You should see a folder called 'MultiMC'.
    6. Select a language that is English. You might have a hard time following this guide otherwise.

    7. Select any Java version that starts with '1.8'.
    8. In the 'memory' section we require you to make some final tweaks.

      Firstly, you need to check the currently installed amount of RAM on your pc.

      Do this by searching for 'about' in Windows, followed by pressing enter.
      You should see a line called 'Installed RAM' which tells you the amount.
      Here are our recommendations for 'Maximum memory allocation':

      Your PC | Allocated to Minecraft

      16GB RAM | 6144MB
      12GB RAM | 5120MB
      8GB RAM | 4096MB or 3584MB

    9. Woohoo, you've set up MultiMC. Good job, now head on over to the login section :kissing_heart:.

    Launcher Setup


    This is very straight forward but I thought I'd add it anyways.


    1. In the top right of MultiMC press the 'Profiles' dropdown and click 'Manage Accounts'.

    2. In the top right of the 'Settings' panel that just opened click 'Add'.

    3. Enter your Minecraft login details and press 'OK'.

    4. That's it. You've logged into your Minecraft account. You can now close the 'Settings' panel. Time to install the Modpack.

    Modpack Installation


    This is how to install any mod pack from FTB, ATLauncher, or CurseForge in MultiMC.


    1. In the top left of MultiMC, press 'Add Instance'.

    2. Fill in a name of your choosing.

    3. In the list on the left, select 'CurseForge'.

    4. In the search bar input 'Eternal' and click 'Search'.

    5. Find and select 'MC Eternal Lite' and press 'OK'.

    6. Double-click your instance to launch the game. Add the server to your server list, IP: ''.

    Custom JVM


    TLDR. This will reduce RAM usage, improve loading times and minimally reduce CPU usage. If you play on a pc with 12GB's of RAM or less and you're not using this, you're not doing it right. Even for users with 12+ GB's of RAM, it's free real estate, go get it!


    1. Head over to AdoptOpenJDK and select 'OpenJDK 8 (LTS)' and 'OpenJ9'.

    2. Download and run the installer.

    3. Accept the terms of the license agreement and click 'Next'.

    4. Unselect the 'Add to PATH' and 'Associate .jar' options. (You only need 'JDK with Eclipse OpenJ9') Then click 'Next'.
    5. Click 'Install' and finish installing.

    6. Open your 'MultiMC' and open the 'Settings'
    7. In the list to the left navigate to 'Java'.

    8. In the 'Java Runtime' section find 'Java path:' and click the navigation box.

    9. Navigate to 'C:/Program Files/AdoptOpenJDK/jdk-'.
    10. Find the 'javaw.exe' and double-click it.
    11. Excellent work. Your MultiMC will now launch using the new JVM, enjoy.

    For people with less than 12GB's RAM


    First of all, before doing this follow the Custom JVM guide above. Otherwise, this is relatively redundant. These are minor tweaks to help you run the game smoothly and work for me with only 3584MB's allocated RAM.

    Custom Java Args:
    1. Open your 'MultiMC' and open the 'Settings'
    2. In the list to the left navigate to 'Java'.

    3. In the 'Java Runtime' section find 'JVM arguments:' and input the following: '-Xmnx500m -Xjit:enableGPU -Xjit:disableGuardedStaticFinalFieldFolding -Xgc:concurrentScavenge'.
    4. Nicely done, your custom arguments are now set.
    In-game Settings:

    Disabling Snooper:
    1. In your Minecraft client go to 'Options...' -> 'Snooper Settings...' and set 'Allow Snooper:' to 'OFF'.
    Enabling Force Threaded Chunk Rendering:
    1. In your Minecraft client go to 'Mods' and search for 'Minecraft Forge'.

    2. Select 'Minecraft Forge' and press 'Config'.

    3. Go to 'Client Settings' and set 'Force threaded chunk rendering' to 'true'.
    Video settings:
    • Other than this if you are having trouble. I'd start by lowering your video settings. Set 'Render Distance' to '6', 'Smooth Lighting' to 'OFF', 'Clouds' to 'OFF', 'Entity Shadows' to 'OFF', and 'Graphics' to 'Fast'.

      It won't look pretty, but you can always increase these settings as you go. Your first priority should be to get the game running smoothly.


    Last edited: May 18, 2021