How to Boost FPS With Performance Mods

If Subnautica 2 is running rough on your PC, you are not alone. The game is still in Early Access and performance can be all over the place, even on decent hardware. The good news is there is a simple mod that can nearly double your FPS without making the game look terrible.

In this guide, we will walk you through exactly how to install the Subnautica 2 Performance Mod step by step. We also have a video guide on this topic on our YouTube channel if you prefer watching.

Optimize Your In-Game Settings First

Before you install the mod, make sure your in-game video settings are already optimized. Open your video settings and set everything to Low.

Under the upscale options, enable TSR and set it to Quality or Balanced. This alone can give you a nice bump in performance.

If you are using an Nvidia RTX graphics card (RTX 2060 or newer), you should see an option for DLSS instead. Enable DLSS and set it to Performance for the best FPS gains. If your card also supports DLSS Frame Generation, enable that too. With Frame Generation on, you might not even need the performance mod, but it can still help.

Back Up Your Save Files

Before installing any mods, it is a good idea to back up your save files. If anything goes wrong, you can just paste them back and everything will be exactly how you left it.

Here is how to find your save files:

1. Press the Windows key and type %LocalAppData% in the search bar.
2. Open the folder that appears.
3. Find the Subnautica2 folder and open it.
4. Inside, you will see a folder called Saved. Copy this entire folder to a safe location like your desktop.

If you ever need to restore your saves, just paste the Saved folder back into the same spot and overwrite the existing one.

Xbox Game Pass players: Your save files are stored in a different location and are synced through your Microsoft account. The path is %LocalAppData%\Packages\[microsoft-package-name]\SystemAppData\wgs\, but honestly you probably do not need to worry about backing these up since Xbox Cloud Saves handles it automatically.

Download the Performance Mod

Head over to the Subnautica 2 Performance Mod page on Nexus Mods. You will need to create a free Nexus Mods account if you do not have one already.

On the mod page, scroll down and click on the Files tab. You will see several preset options:

• Balanced Performance - A good middle ground. Reduces some effects while keeping the game looking solid. Expect around 100 FPS if you were getting 80 before.
• Ultra Performance - Cuts more effects for maximum FPS. The game still looks perfectly playable. Expect around 130 FPS from the same 80 FPS baseline.

Pick the preset that fits your needs and click Manual Download next to it. Wait for the file to finish downloading.

Install the Mod

Once the file is downloaded, follow these steps:

1. Find the downloaded file in your Downloads folder.
2. Right-click it and select Extract All (or use WinRAR/7-Zip if you have it).
3. Open the extracted folder. You should see a file called Engine.ini.
4. Right-click on Engine.ini, select Properties, and check the Read-only box. Click Apply. This is important because it prevents the game from overwriting your modded settings.

Now you need to copy this file to the right location.

For Steam Players

1. Press the Windows key and type %LocalAppData% again.
2. Open the folder and navigate to Subnautica2 > Saved > Config > Windows.
3. Copy your modded Engine.ini file into this folder and replace the existing one.

The full path is:
%LocalAppData%\Subnautica2\Saved\Config\Windows\

For Xbox Game Pass Players

The process is the same, but your config folder is in a slightly different spot:

%LocalAppData%\Subnautica2\Saved\Config\WinGDK\

Navigate there and paste the Engine.ini file, replacing the existing one. Make sure Read-only is still checked after copying.

That is it. Launch the game and enjoy your boosted FPS.

FPS Results

Here is what you can expect after installing the mod (tested on lowest in-game settings):

Your results will vary depending on your hardware, but the percentage improvement should be similar across most systems.

How to Uninstall the Mod

If you want to go back to the default settings, just navigate back to the config folder (the Windows or WinGDK path from earlier) and delete the Engine.ini file you placed there. The game will regenerate a fresh one the next time you launch it.

Verify Game Files if Something Goes Wrong

If the game starts acting up after modding, you can verify your game files through Steam:

1. Open your Steam Library.
2. Right-click on Subnautica 2 and select Properties.
3. Go to the Installed Files tab.
4. Click Verify integrity of game files.

Steam will check all your game files and redownload anything that is missing or corrupted. This does not affect your save files or the Engine.ini config, so you may need to remove the modded Engine.ini separately if that was causing the issue.