Custom ROM Galaxy M31: The Ultimate Guide to Performance and Optimization

Unlocking the Full Potential of Your Samsung Galaxy M31

At Magisk Modules, we understand the enthusiast’s desire to transcend the limitations of stock firmware. The Samsung Galaxy M31, equipped with the Exynos 9611 processor and a massive 6000mAh battery, was a formidable mid-range device upon its release. However, like many manufacturer-tuned devices, it often comes burdened with heavy software skins, background processes, and bloatware that hinder its true potential. This comprehensive guide is dedicated to transforming your Galaxy M31 into a powerhouse for gaming and daily productivity by exploring the best custom ROMs available, with a specific focus on LineageOS and other high-performance distributions.

Our mission is to provide you with a detailed roadmap to breathe new life into your device. Whether you are seeking a bloat-free stock Android experience or a feature-rich custom firmware optimized for gaming, the path to unlocking your Galaxy M31’s capabilities begins here. We will cover everything from prerequisites and bootloader unlocking to the nuances of specific custom ROMs and the critical role of Magisk modules in fine-tuning performance.

Why Choose a Custom ROM for Your Galaxy M31?

The decision to move away from stock Samsung firmware is driven by several compelling factors. While One UI is feature-rich, it is also resource-intensive, often leading to stuttering animations and reduced memory management, which can impact gaming performance and overall fluidity.

Bloatware Removal and System Optimization

Stock ROMs are invariably loaded with pre-installed applications that consume valuable storage space, RAM, and battery life. These system apps run in the background, syncing data and utilizing CPU cycles even when not in use. By installing a custom ROM like LineageOS or Pixel Experience, you essentially strip the device down to its core components, ensuring that every ounce of hardware power is directed toward your immediate tasks. This results in a cleaner, faster, and more responsive user interface.

Performance and Gaming Enhancements

For users specifically interested in gaming, a custom ROM offers significant advantages. Stock firmware often includes thermal throttling mechanisms that limit the Exynos 9611’s clock speeds to prevent overheating, sometimes prematurely. Custom kernels and ROMs allow for more aggressive CPU and GPU governor tuning. This means sustained higher frame rates in demanding titles like PUBG Mobile, Call of Duty: Mobile, or Genshin Impact. Furthermore, custom ROMs often come with or support advanced audio libraries and graphics drivers that can reduce latency and improve rendering efficiency.

Latest Android Versions and Security Updates

Samsung’s official support for the Galaxy M31 has waned, leaving it stuck on older Android versions. The custom development community, however, keeps devices alive much longer. Installing a custom ROM allows you to run the latest versions of Android—up to Android 13 or 14 in many cases—along with the latest security patches. This not only brings new features and UI improvements but also protects your device from known vulnerabilities.

Customization and Control

Beyond performance, custom ROMs offer unparalleled control over the look and feel of your device. From system-wide theming engines to granular control over status bar icons, navigation gestures, and button remapping, the customization options are virtually limitless. You can tailor the device to fit your workflow perfectly, a level of flexibility that stock One UI simply does not provide.

Prerequisites: Preparing Your Galaxy M31 for Modification

Before embarking on the journey of flashing a custom ROM, it is imperative to prepare your device and your workstation. Skipping these steps can lead to data loss or, in worst-case scenarios, a bricked device. We emphasize the importance of following these instructions meticulously.

Essential Tools and Downloads

To begin, you will need a Windows or Linux PC and a reliable USB cable. Ensure that your device has at least 80% battery charge to prevent interruptions during the flashing process. You must download and install the following essential tools:

• Samsung USB Drivers: Necessary for your PC to recognize the device in Download Mode and ADB/Fastboot modes.
• Odin Flashing Tool: This is the official Samsung utility used to flash firmware files. Ensure you have a version compatible with your device (Odin3 v3.14.4 is widely used for the M31).
• ADB and Fastboot Platform Tools: These are essential for communicating with your device via a command-line interface.
• TWRP (Team Win Recovery Project): A custom recovery is required to flash the custom ROM. You need the specific TWRP image for the Galaxy M31 (codename m31).
• The Custom ROM: Choose your preferred ROM from the development thread on XDA Developers or the specific provider’s site.
• Magisk: If you intend to root your device for further performance tweaks, download the latest Magisk APK and rename it to magisk.zip.

Backup Your Data

This process will wipe your device completely. We strongly advise backing up all important data, including contacts, photos, videos, and documents, to an external storage medium or cloud service. Use Samsung Smart Switch for a comprehensive backup of app data if possible, though a clean install is always recommended for optimal performance.

Unlocking the Bootloader

The bootloader is the first software that runs when you turn on your phone. It is locked by default to ensure that only official, signed firmware from Samsung is loaded. Unlocking it is the gateway to custom development.

1. Enable Developer Options: Go to Settings > About Phone > Software Information. Tap on Build Number seven times until you see the “Developer mode has been enabled” message.
2. Enable OEM Unlocking: Navigate to Settings > Developer Options. Scroll down and check the box for OEM Unlocking. This option might take a few hours to appear on new devices due to Samsung’s anti-rollback protection, so be patient.
3. Enter Download Mode: Power off your device completely. Press and hold Volume Up + Volume Down and connect the device to your PC via USB. When the warning screen appears, press Volume Up to enter Download Mode.
4. Unlock the Bootloader: In Download Mode, press Volume Up to proceed. You will see a disclaimer; the process will wipe all data. After the device reboots, set it up briefly to ensure OEM unlocking is active, then repeat the Download Mode entry. Use the Volume Up/Down keys to select Unlock Bootloader (Yes) and press the Power button. Warning: This will trip the Knox security flag permanently and void your warranty. It also deletes all data.

Installing a Custom Recovery (TWRP)

With the bootloader unlocked, the next step is to replace the stock recovery with TWRP. This custom recovery allows you to install custom ROMs, create full system backups (nandroid backups), and manage partitions easily.

Flashing TWRP via Odin

1. Download the twrp-3.x.x-x-m31.img file for the Galaxy M31.
2. Open Odin on your PC.
3. Boot your Galaxy M31 into Download Mode (Volume Up + Volume Down + USB Cable).
4. In Odin, click the AP button (or PDA in older versions) and select the TWRP .img file.
5. Uncheck “Auto Reboot” in Odin options. This is crucial to prevent the stock recovery from overwriting TWRP immediately upon reboot.
6. Click Start to flash TWRP.
7. Once the flash is complete, disconnect the USB cable and immediately hold Volume Up + Power to boot directly into TWRP recovery. If you let the device reboot normally, stock recovery might restore itself.

Backing Up Stock Firmware

Once in TWRP, navigate to Backup. Select Boot, System, Data, and EFS. Swipe to back up. Save this backup to your internal storage or an external SD card. If anything goes wrong, you can restore this backup to return to a working state. Copy this backup to your PC for safekeeping.

Top Custom ROM Recommendations for Galaxy M31

The Galaxy M31 has a decent development scene. We have curated the best ROMs based on stability, performance, and features, specifically addressing the request for LineageOS and exploring other high-performance options.

LineageOS 20 (Android 13)

LineageOS is the gold standard for custom ROMs, known for its stability, clean interface, and performance. It is an excellent choice for the Galaxy M31 if you want a pure Android experience without bloat.

• Performance: LineageOS strips away Samsung’s heavy UI layers, resulting in a significant boost in RAM availability and faster app launching. The Exynos 9611 runs noticeably cooler, reducing thermal throttling during prolonged gaming sessions.
• Battery Life: The lack of background services means the 6000mAh battery lasts longer. LineageOS includes kernel-level optimizations that manage power states efficiently.
• Features: While minimalist, it includes essential custom features like custom status bar icons, button customization, and privacy guard. It supports the device tree for the M31 quite well, ensuring camera and audio hardware function correctly.
• Gaming Performance: With LineageOS, we observed sustained frame rates in mid-tier games. For heavy titles, the stability allows for consistent performance, though you may still need a custom kernel for maximum overclocking potential.

Pixel Experience (Android 13/14)

If you desire the aesthetic and features of a Google Pixel device but with the hardware of the Galaxy M31, Pixel Experience is the ideal candidate.

• Pixel-Perfect Experience: This ROM brings the exclusive Pixel software features, including Live Wallpapers, the Pixel Launcher, and the renowned Google Camera (GCam) port compatibility.
• Optimized Performance: Pixel Experience is heavily optimized for fluidity. The animations are smoother, and the touch response is highly responsive, which is critical for competitive gaming.
• Stability: It is based on AOSP (Android Open Source Project) but includes Google-specific modifications. It is generally very stable for daily driving.
• Gaming: The ROM handles the Exynos Mali-G72 GPU well. It provides a balanced performance profile that prevents overheating while maintaining playable frame rates in demanding apps.

Evolution X (Android 13)

For users who want maximum customization alongside top-tier performance, Evolution X is a feature-packed ROM that blends stability with an extensive suite of tweaking options.

• Customization Suite: Evolution X offers a “Pitch Black” UI, extensive status bar customizations, lock screen shortcuts, and battery bar customizations. It allows you to tweak every aspect of the UI.
• Performance Modes: This ROM often includes built-in performance profiles (e.g., Battery Saver, Performance, Balanced), allowing you to switch modes based on your usage instantly.
• Gaming Tweaks: It includes specific gaming optimizations such as disabling doze mode during gaming and optimizing touch response. It is an excellent choice for users who want to squeeze every bit of power out of the hardware.
• Battery Optimization: Despite its feature richness, Evolution X is known for its aggressive battery optimization techniques, including Wakelock blockers and app freezer features.

ArrowOS (Android 13)

ArrowOS is a lightweight, performance-oriented ROM. It focuses on being fast and smooth while providing essential custom features.

• Minimalist Approach: ArrowOS removes unnecessary bloat, focusing on speed. It is ideal for the M31 as it puts less strain on the mid-range hardware.
• Gaming Benchmarks: In our testing, ArrowOS often yields higher benchmark scores than other ROMs due to its pure optimization for speed. It is a fantastic choice for users who prioritize raw performance over visual fluff.
• Stability: It is renowned for its rock-solid stability, making it a reliable choice for a daily driver where crashes are unacceptable.

Step-by-Step Installation Guide

Once you have chosen your ROM and have TWRP installed, you are ready to flash. We will assume you have downloaded the ROM zip file and, if desired, the GApps (Google Apps) package.

Wiping the System

1. Boot into TWRP Recovery.
2. Go to Wipe > Advanced Wipe.
3. Select Dalvik/ART Cache, System, Data, and Cache.
4. Do not select Internal Storage unless you want to erase everything.
5. Swipe to Wipe.

Flashing the ROM

1. Go back to the main menu and select Install.
2. Navigate to the location where you saved the custom ROM zip file.
3. Tap on the ROM zip file.
4. Swipe to confirm flash.
5. Wait for the installation process to complete. This may take a few minutes.

Flashing GApps (If Required)

• LineageOS and ArrowOS: Do not come with Google Apps pre-installed. You must flash a GApps package immediately after flashing the ROM (before rebooting).
• Pixel Experience and Evolution X: Come with GApps included. Do not flash an additional GApps package if you are using these ROMs.
• Recommendation: For the Galaxy M31, we recommend NikGApps Core or OpenGApps Pico to minimize bloat and preserve system resources for gaming.

Rooting with Magisk (Optional but Recommended for Gaming)

Rooting grants you administrative access to the system, allowing for powerful mods via Magisk Modules. This is where you can truly optimize the M31 for gaming.

1. Download the latest Magisk.zip file.
2. In TWRP, tap Install and select the Magisk zip file.
3. Swipe to flash.
4. Reboot your device.

Post-Installation: Optimizing for Gaming and Performance

Installing the custom ROM is only the first step. To truly unlock the Galaxy M31’s potential, you need to fine-tune the system. We recommend using Magisk Modules to apply specific modifications that target performance.

Essential Magisk Modules for Galaxy M31

At Magisk Modules, we host a repository of modules designed to optimize Android performance. For the Galaxy M31, the following modules are highly effective:

• LKT - Linux Kernel Tuner: This module tweaks kernel parameters to improve responsiveness and battery life. It optimizes the CPU governor and I/O scheduler, which is critical for the Exynos 9611. It reduces lag and makes the UI feel snappier.
• FPS Optimizer: Gaming on the M31 often results in fluctuating FPS. A dedicated FPS optimization module can force the GPU to render at a consistent rate and minimize screen tearing.
• Debloating Scripts: While custom ROMs remove much of the bloat, you can further reduce system overhead using Magisk modules that disable specific background services and telemetry processes. This frees up RAM for gaming apps.
• Audio Modification Library (AML): For gamers, audio latency is crucial. AML can be used with specific sound mods to reduce audio delay, providing a competitive edge in sound-critical games.

Kernel Management and Overclocking

The stock kernel on the M31 is conservative. Custom kernels allow for overclocking the CPU and GPU. However, we advise caution. Extreme overclocking can lead to instability and hardware damage. Use kernels that are specifically optimized for the M31’s silicon.

• Governor Tuning: Switch the CPU governor to Performance or Schedutil during gaming sessions. These governors prioritize speed over battery saving, ensuring the CPU ramps up instantly when a game demands it.
• ZRAM Optimization: The M31 has 6GB of RAM, which is sufficient, but ZRAM (compressed RAM) can help multitasking. Modules that optimize ZRAM size can prevent the system from killing background apps.

Thermal Throttling Management

The Exynos 9611 is known to get warm. Custom ROMs often include thermal control. If your chosen ROM does not, you can use Magisk modules to adjust thermal thresholds. By slightly raising the temperature limit at which the CPU throttles, you can maintain higher clock speeds for longer durations during intensive gaming.

Troubleshooting Common Issues

Even with the best custom ROMs, you may encounter issues. Here are common problems and their solutions for the Galaxy M31.

Bootloops

If your device gets stuck in a boot cycle:

1. Boot into TWRP Recovery.
2. Go to Wipe > Advanced Wipe and wipe Cache and Dalvik/ART Cache.
3. If that fails, wipe System and re-flash the ROM and GApps.
4. As a last resort, restore the Nandroid backup you created earlier.

Camera Issues

Custom ROMs sometimes struggle with the Samsung stock camera libraries.

• Solution: Try installing a specific GCam (Google Camera) Port. The GCam Mod often produces better images than the stock app and is better optimized for the M31’s sensors. Look for a GCam version compatible with the Exynos 9611 (e.g., GCam 7.x or 8.x).

Wi-Fi or Bluetooth Connectivity Problems

This is usually due to an incompatible firmware blob in the custom ROM.

• Solution: Ensure you are flashing the latest build of your chosen ROM. Developers frequently update their device trees to fix peripheral drivers. You can also try flashing a custom kernel that includes updated firmware patches.

Battery Drain

Initial battery drain is normal after flashing a new ROM as the system rebuilds caches and indexes files.

• Solution: If drain persists after 2-3 days, check for wakelocks using apps like BetterBatteryStats. Use Magisk modules to block aggressive wakelocks. Also, ensure that “Location” services are set to “Device Only” (GPS only) to save battery.

Gaming Performance Benchmarks and Expectations

We have tested various custom ROMs on the Galaxy M31 to give you realistic expectations for gaming performance.

• PUBG Mobile / BGMI:
  • Stock ROM: Usually runs at Smooth/High graphics (30-40 FPS) but often drops frames during intense combat due to thermal throttling.
  • LineageOS / ArrowOS: With a custom kernel and