Cleaning up RAM on Xiaomi Redmi Note 9: the full guide

Why Redmi Note 9 is slowing down and how it relates to RAM

Your Xiaomi Redmi Note 9 is getting hung up, apps are spontaneously shutting down and animations are twitching? 90% of the time, it's overloaded RAM. Despite the 3/4/6 GB of RAM in different versions of the model, MIUI aggressively caches background processes, which over time leads to "memory leaks," especially after 1-1.5 years of use, when the system is clogged with remnants of remote applications and incorrect services.

The manufacturer claims that the Redmi Note 9 based on the MediaTek Helio G85 (or Helio G90T in the Pro version) is optimized for multitasking, but in practice users are faced with a system feature of MIUI: when you fill up more than 85% of RAM, the smartphone begins to forcibly “kill” active applications, even if they are in the foreground. This is not a defect – this is how the memory management algorithm in Xiaomi firmware works.

Method 1: Manually release RAM through the security menu

The fastest method is to use a built-in cleaning tool, which does not require superuser rights and works even on blocked downloaders:

1. Open Settings → About Phone and click on MIUI Version 7 times to activate Developer Mode (if not already activated).
2. Return to the main settings menu and go to Additional → Security.
3. Slip on the "Cleaning" icon (broom sign) in the upper right corner.
4. Select the RAM tab and click Clean.

This method frees up to 30-40% of RAM, but has a drawback: after 10-15 minutes, the background MIUI processes will again fill the RAM.

⚠️ Note: Do not use this method more than 1 time per hour. Frequent forced cleaning of RAM can damage the cache of system applications, which will cause errors such as "App has stopped" (com.android.systemui).

Method 2: Configure autocleaning through hidden MIUI settings

MIUI hides advanced memory management settings, but you can activate them through the Developer Settings:

1. Go to Settings → Additional → For developers.
2. Scroll to the App section and find options: Do not save actions - install 3 processes (this will limit background multitasking). Process limit - select the Standard Limit (for 4 GB of RAM) or Max. 2 process (for 3 GB). Clear RAM when blocked - turn on this option.

Save the changes and restart the device.

These settings will reduce background activity by 40-50%, but some apps (such as instant messengers) may stop sending notifications. For critical services (WhatsApp, Telegram), add them to the exceptions:

Settings → Applications → Application Management → [Select messenger] → Battery → Without restrictions


Settings → Applications → Permissions → Autorun → Include for messengers

💡

If the changes start to drain faster, return the process limit to the standard limit. Too aggressive cleaning of RAM causes the processor to reboot applications more often, which increases power consumption.

Method 3: Use ADB-deep-cleaning

For advanced users, there is a method of cleaning RAM through Android Debug Bridge (ADB), which allows you to manually control processes that are usually hidden from the user.

• 🖥️ Computer with installed ADB Tools
• 📱 Included debugging by USB on a smartphone (Settings) → For developers → Debugging by USB)
• 🔌 Cable USB (preferably original)

Connect your phone to your PC and execute commands in the terminal:

adb shell


su




echo 3 > /proc/sys/vm/drop_caches # Clearing the cache of pages




Killall -9 com.miui.home # Launcher Restart




setprop persist.sys.miui_optimize_ram 1 # Enable RAM Optimization

These teams:

• Clear the cache of the kernel (not to be confused with Dalvik cache!)
• Re-start the system launcher, which often “flows” memory
• Activate hidden mode of optimization of RAM from Xiaomi

⚠️ Attention: Killall Team -9 com.miui.home will cause the wallpaper and widgets to disappear for a short time. They will recover after the reboot. 1 Once a day, it can disrupt the miui.system.

Method 4: Optimization through Engineering Menu (MTK)

The Redmi Note 9 on the MediaTek processor has a hidden engineering menu where you can manually configure memory management settings. Careful: incorrect changes can lead to unstable work!

To get on the menu:

1. Open the Phone app.
2. Enter the code ##36446337## (to check the MTK version)
3. Then type ##4636## and select Phone Information.
4. Select the item for testing → Memory Information.

In this menu you will see detailed information about the use of RAM.

After the changes, restart the device. These settings are reset after the MIUI update, so you need to re-apply them after each update.

Method 5: Alternative launchers and lightweight firmware

If standard methods do not help, consider using:

• 📱 Lightweight launchers: Nova Launcher (turn off animations in settings), Lawnchair (with gesture support) Smart Launcher 5 (automatic app sorting)
• 🔄 Custom firmware: Pixel Experience (pure Android without a sleek Android) MIUI) LineageOS (stable, but without branded Xiaomi features) Xiaomi.eu (MIUI softwareless)

Switching to custom firmware requires unlocking the bootloader and installing it via TWRP. This voids the warranty and can lead to hard-brick error.

• Increase free RAM by 20-30% by removing MIUI system processes
• More aggressive memory management in AOSP-firmware
• No background processes for Mi Cloud, Mi Video, and other pre-installed applications

⚠️ Note: On the Redmi Note 9 with MediaTek processor, bootloader unlocking is officially supported, but requires a wait of 7 days after the Mi Account is tied. MTK Bypass) may lead to blocking IMEI.

💡

Lightweight launchers give an increase in free RAM by 100-300 MB, and custom firmware - up to 1 GB. However, the latter option requires technical skills and deprives of warranty.

What will NOT help to clear the RAM (common myths)

There are dozens of memory cleanup tips online that don't really work or even harm the system.

• ❌ "Play Market’s ‘Task Killers’: Apps like Clean Master or DU Speed Booster doesn’t clean up RAM more effectively than built-in tools, but it does run background processes that clog up memory. Xiaomi even added these apps to the blacklist in the company’s website. MIUI 12+.
• ❌ Disable animations: Adb shell settings put global window_animation_scale 0 Speeds up the interface, but doesn’t free up RAM – it just makes transitions between screens instantaneous.
• ❌ Cache Clearing via Recovery: Resetting Dalvik Cache helps after updates, but does not affect RAM – it only clears data to speed up application launches.
• ❌ Closing all applications manually: Android and MIUI Optimized to work with cached processes. Forced closure increases the workload on the processor when you need this application again.

The only way to do this is to disable unnecessary system applications through ADB:

adb shell pm uninstall -k --user 0 com.miui.analytics


adb shell pm uninstall -k --user 0 com.xiaomi.ab

But even this will give an increase of only 50-100 MB of RAM, but reduce background activity.

FAQ: Frequent questions about cleaning RAM on the Redmi Note 9