How to Optimize Xiaomi Redmi Note 9: A Complete Guide to Maximum Performance

Xiaomi Redmi Note 9 remains one of the most popular budget smartphones even years after its release. However, over time, many users face slowdowns, fast battery drain and memory shortages. G85 4 GB of RAM is quite competitive, and in the wrong setting of the system, clogged cache and firmware features MIUI.

This article will help to return the smartphone to its former speed without radical measures like factory reset. MIUI, Turning off background processes, hardware tricks (performance modes, cooling), and battery and memory nuances. All methods tested on current versions MIUI and do not require root rights.

We pay special attention to hidden functions. MIUI 14/15, Xiaomi doesn't advertise, but it can radically improve the user experience, for example, setting the "Battery Savings" mode correctly can extend the autonomy of the user. 30%, a disabling unnecessary system services - to speed up the launch of applications on 20-40%.

1. Diagnostics of the current state of the smartphone

Before you optimize the Redmi Note 9, you need to understand what is stopping the system, and 80% of the time, the problem is:

• 📱 Overloaded memory (less than 1 GB of free RAM)
• 🗑️ Clogged cache (more than 3 GB of junk files)
• 🔋 Worn-out battery (capacity below 80% of nominal value)
• 🤖 Background processes (more than 30 active applications)

Use the built-in tools for diagnosis MIUI:

1. Open the Settings. → The phone. → System state - here displays CPU load, RAM and temperature.
2. Go to Settings. → Battery. → Battery status – check the current capacity (normal for the battery) 2-summer-smartphone: 85-90%).
3. Launch Security → Cleaning – the system will show the amount of unnecessary files.

Critical indicators that require urgent optimization:

⚠️ Note: If the processor temperature exceeds 60°C in plain, this indicates a hardware problem (dried thermal paste, damaged battery). In this case, the optimization of the software will not help - you need repairs.

2. Cleaning the system: remove garbage and cache

MIUI It's known for actively cacheing data, but rarely cleaning it automatically. 9 may accumulate before 5-7 GB of unnecessary files: remnants of deleted applications, temporary messenger files, duplicate photos and game cache. Cleanup gives you an increase in performance on the Internet. 15-25%.

Step-by-step:

1.Appendix cache:

• 🧹 Go to Settings. → Annexes → Application management.
• 📊 Sort by cache size (tap on "Cache size»).
• 🗑️ For each application (especially social networks and games) click “Clear cache».

Systemic debris:

• 🔍 Open the Security app → Cleanup → Deep cleaning.
• ✅ Mark all items (cache, residual files, unnecessary ones) APK).
• 🚮 Click "Clean" - it will free you. 1-3 GB space.

Duplicates and unnecessary files:

• 📷 Use the built-in Gallery app → Albums. → Duplicate to find repetitive photos.
• 🎵 Check the audio folder in Music – unnecessary recordings often accumulate there.
• 📁 Downloads folder is usually full of outdated files (APK, PDF, ZIP).

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After cleaning, restart the smartphone – this will allow you to MIUI Re-index files and speed up the system 10-15%.

3. MIUI Optimization: Hidden Settings and Tweaks

Firmware MIUI It contains dozens of hidden features that can be used to speed up the Redmi Note 9. Most of them are not documented, but are available through developer settings or special combinations.

Activation of the developer mode:

1. Go to Settings. → The phone.
2. Tap 7 times on the MIUI version.
3. Enter the password from your Mi Account (if requested).

Key settings for optimization:

How to change it:

1. Open the settings → Additional → for developers.
2. Find the parameters from the table and set the recommended values.
3. To apply the changes, restart the smartphone.

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Disabling animation of windows and transitions speeds up the interface 20-30%, But it makes it less smooth. If you care about aesthetics, leave the animations on. ×0.5.

Hidden functions MIUI resource-saving:

• 🔄 Autoclean RAM: Include in Settings → Battery. → Cleaning RAM (set the interval 1 hour).
• 📵 Background activity restriction: For each application in Settings → Battery. → Select applications to set "Limited».
• 🌙 Dark theme: Reduces the load on the processor when displaying the interface (included in Settings) → Screen. → Dark subject).

⚠️ Note: Do not disable system applications through Settings → Applications without understanding their purpose, such as deactivating com.xiaomi.misettings will cause your settings to fail. MIUI.

4. Battery setup: how to extend autonomy

Redmi Note battery 9 on 5020 mAh should provide 1.5-2 In practice, many users only get 8-12 The reason is aggressive energy consumption by background processes and suboptimal settings. MIUI.

Top.-5 charge-saving:

• 🔋 Ultraeconomics: Included in the 15% Charge, but it can be activated manually in Settings → Battery. → Battery modes, extends the work 30-50%.
• 📶 Limitation 4G: If you are not using the mobile Internet, switch to 3G In Settings → SIM-maps and mobile networks → Type of network.
• 📍 Disabling geolocation: In Settings → Confidentiality → Permits → Geodata disable access for unnecessary applications.
• 🔄 Autosynchronization: Disable in Settings → Accounts and sync to save traffic and battery.
• 🌡️ Temperature control: If the battery is heated above 40°C, use the Battery Savings mode (Settings) → Battery).

Calibration of the battery (if the smartphone suddenly turns off when 20-30% charge):

1. Discharge the phone before automatically shutting down.
2. Charge up to 100% without interruption (use the original adapter) 18W).
3. Repeat the cycle 2-3 times.

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If the battery is swelling (as seen from the screen raised), DO NOT calibrate it - it's dangerous! Replace the battery at the service center immediately.

Optimal charging settings:

• ⚡ Use the original cable and adapter (not fast charging from other brands).
• 🛌 Don’t leave your phone on overnight charging – it shortens battery life.
• 🔄 Charge to 80-90%, before 100%, If you plan to not use your smartphone for a long time.

5. Performance optimization for games and heavy applications

Redmi Note 9 on Helio G85 It can run modern games (like Genshin Impact or Call of Duty Mobile), but you have to set up the system correctly. FPS, overheating and rapid discharge.

Settings for gamers:

• 🎮 Game mode: Enable in Settings → Special facilities → Game mode. This turns off notifications and optimizes resources.
• ⚙️ Graphic settings: In games, set the Average graphics settings and 60 FPS (if maintained).
• 🧊 Cooling: Use a game cooler or play in temperatures below 25°C (e.g. in a cool room).
• 🔋 Charging during the game: Connect charging (preferably original) 18W), avoiding productivity loss.

Fine tuning through ADB (for advanced users):

adb shell settings put global force_high_performance true


adb shell settings put global stay_on_while_plugged_in 3

These commands force the maximum performance mode and prevent the screen from turning off when charging.

List of games that Redmi Note 9 mid-size (30-60 FPS):

• 🎮 PUBG Mobile (HD + 40 FPS)
• 🎮 Call of Duty Mobile (Medium) + 60 FPS)
• 🎮 Genshin Impact (Low) + 30 FPS)
• 🎮 Free Fire (Ultra) + 60 FPS)
• 🎮 Minecraft (max. settings)

⚠️ Note: If there are drawdowns in the game FPS below 20, lower the screen resolution to 720p This will give you a performance boost on the display. 15-20%.

Memory Management: How to Free Up Space and Speed Up Storage

Redmi Note 9 squash 64 or 128 GB of memory, but even 128 GB can fill quickly due to features MIUI. The system reserves to 10 GB for updates, and the cache of applications takes more 5-7 GB, if less free 5 GB, the smartphone starts to slow down.

How to make room:

• 📸 Photos and Videos: Move them to Google Photos (up to 15GB free) or an external drive.
• 🎵 Music and podcast: Use streaming (Spotify, Yandex Music) instead of storing files.
• 📦 APK-Files: Remove application installers from the Downloads folder.
• 🗑️ Cash cards: Clear the cache of Google Maps or Yandex Maps (can weigh up to one). 1-2 GB).

Storage optimization:

1. Go to Settings. → Warehouse.
2. Slip on "Free up a place» — MIUI Remove unnecessary files.
3. Include “Waste Cleanup” in Settings → Battery and performance → Cleanup.

Use of external memory:

• 📁 Redmi Note 9 supports microSD up to 512 GB (format) FAT32 exFAT).
• 🔄 Move the apps to the map: Settings → Annexes → Select an application → Warehouse → Change.
• ⚠️ Not all apps support portability (such as WhatsApp or Banking apps).

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If you use a microSD, select a class card. A2 (for example, Samsung EVO Plus, she's in. 2-3 times faster than normal cards and does not slow down the work of applications.

Formatting as internal memory (advanced method):

1. Insert the microSD into the slot.
2. Go to Settings → Storage → Memory Map.
3. Select “Format as internal memory” (all data will be deleted!).
4. After formatting, transfer the data from the internal memory.

⚠️ Note: Once formatted as internal memory, the card cannot be used in other devices without being completely cleaned, and it can slow down if the card is slow.

7.Firmware and kernel updates: when it helps

Xiaomi regularly releases updates for the Redmi Note 9, but not all of them are equally useful. Some firmware contains bugs that, on the contrary, slow down the smartphone. It is important to understand when the update will help, and when it is better to stay on the current version.

How to check the relevance of the firmware:

1. Go to Settings → About the phone → System update.
2. Compare the current version MIUI The latest stable builds on en.miui.com.

When to update:

• ✅ There are fixes for critical bugs (for example, quick battery discharge).
• ✅ New version of Android (for example, the transition from Android 10 to 11).
• ✅ Optimization for games or cameras.

When NOT to be updated:

• ❌ If the current firmware is stable and the new one contains bug complaints (check the forum reviews).
• ❌ If the update weighs more than 2GB, it could be a switch to a new version of Android that requires a reset.
• ❌ If you have a modified firmware (for example, custom recavery).

How to update without losing data:

1. Make a backup copy in Settings → Additionally. → Backup and reset.
2. Connect to Wi-Fi (update "over the air" weighs in) 1.5-2.5 GB).
3. Charge the battery to 50% or more.
4. Click “Download and install” in the update menu.

Alternative Firmware (for experienced users):

• 📱 MIUI EU — European version without Bloatware (unnecessary Chinese applications).
• 🤖 LineageOS – “pure” Android without a shell MIUI.
• ⚠️ For installation, unlocking the loader and custom recavery are required (TWRP).

8 Hardware optimization: when software methods do not help

If all of the above methods fail, the problem may be in the hardware. Redmi Note 9 often suffers from:

• 🔋 Battery wear (capacity below 70%).
• 🔥 Overheating due to dried thermopaste.
• 💾 Damaged memory (bad blocks on a flash drive).
• 📡 Bad signal network (communication module is operating at the limit).

Diagnostics of hardware problems:

What you can do on your own:

• 🔧 Replace thermopaste: Disassemble the smartphone (need a mediator and a screwdriver) T4). Clean the old paste with alcohol. Apply a new thermal paste (e.g. Arctic) MX-4).

Battery replacement

1. Buy the original battery (article: MB09).
2. Unplug the old battery (use a plastic shoulder blade).
3. Connect a new battery and check the contacts.

⚠️ Warning: If the smartphone doesn't turn on after the battery is replaced, check to connect the display plume. Often when disassembling it, it accidentally disconnects.

FAQ: Frequent questions about Redmi Note optimization 9