Xiaomi Redmi 9 with its 3 or 4 GB of RAM often starts to slow down after a year or two of active use. The reasons are standard: background processes, app cache, unoptimized MIUI firmware. But before you run to the service or think about buying a new smartphone, try these methods. In 80% of cases, the problem can be solved without radical measures - competently manage resources.
This article is only a proven method that works on Redmi 9 (including Redmi 9A/9C/9T modifications) with current versions of MIUI 12-14. No universal “advice for all Androids” – only specific instructions for your model. And if you have already tried standard cleaning through the menu – no problem: we will reveal hidden features of the system, which are silent even official guides.
Why is Redmi 9 “suffocating” from a lack of RAM?
The MediaTek Helio G35/G80 processor paired with 3-4 GB of RAM should theoretically cope with everyday tasks.
- 🐢 Hangings when switching between apps (especially in Telegram, Chrome, Instagram).
- 🔄 Reboots when starting games (Free Fire, PUBG Mobile).
- 📱 Message “lacking memory” even with 1-1.5 GB of free RAM.
The culprits:
- MIUI background processes: The system aggressively caches data but doesn't clean it well. For example, com.miui.analytics can take up to 300MB of RAM in the background.
- Apps-gluttons: messengers, social networks and launchers (MIUI Launcher) do not free up memory after closing.
- Android kernel errors: Redmi 9 with Android 10/11 encounters a bug called lmkd (low memory killer), which incorrectly kills processes.
Interesting fact: after upgrading to MIUI 14 on Redmi 9, some users reported a 20 to 30 percent increase in free RAM due to kernel optimization, but if the upgrade is not available, you will have to manually act.
Method 1: Manually release RAM through a hidden menu
MIUI hides useful tools in the developer menu to activate them:
- Go to Settings. → The phone.
- Tap 7 times on the MIUI version (you will be notified “You became a developer”).
- Return to the main settings menu and open Additional → for developers.
Now, look for the Process Limit option (or Background Limit in newer versions) and manually specify how many applications will run in the background:
- 🔘 Without background processes – a radical method, but can lead to frequent reboots of applications.
- 🔘 Process Maximum 2 – Optimal balance for Redmi 9 with 3GB of RAM.
- 🔘 4 process maximum – suitable for 4 GB of RAM, but only if you do not play heavy games.
Activate Developer Mode (7 taps according to MIUI)
Set the limit of background processes on the "Maximum 2"
Turn off window animation (slow down work)
Reboot your phone to apply changes-->
⚠️ Note: If notifications from messengers have stopped coming after the process is limited, add them to the exceptions in the Battery Optimization section.
Method 2: Cleaning the cache of system applications
The MIUI cache can take up to 1-1.5 GB of RAM, even after rebooting, to clean it up:
- Go to Settings → Applications → Application Management.
- Slip on three dots in the upper right corner and select Show System.
- Find and clear the cache from the following applications: com.miui.home (Launcher) com.android.systemui (System interface) com.miui.analytics (Xiaomi Analytics) com.xiaomi.market (Mi App Store)
It can be used to speed up the process. ADB-command (requires a connection to the PC):
adb shell pm clear com.miui.home
adb shell pm clear com.android.systemuiThis method releases up to 500 MB of RAM immediately after execution, but the effect is temporary - after 1-2 days, the cache will accumulate again. For automatic cleaning, install Tasker with a profile to clean the cache once a day.
What happens if you clear the data (not the cache!) of system applications?
Method 3: Disabling unnecessary MIUI services
Xiaomi preinstalles dozens of services that work in the background and eat up RAM, some of which can be safely disabled:
| Service | What's he doing? | Can I turn it off? |
|---|---|---|
| com.miui.analytics | Collection of usage statistics | ✅ Yes, no consequences) |
| com.xiaomi.ab | Xiaomi Advertising Services | ✅ Yes (reduces the amount of advertising) |
| com.miui.bugreport | Error reports | ⚠️ Unless you send a log in support |
| com.miui.daemon | System processes management | ❌ No (critical for stability) |
To disable the service:
- Go to Settings → Applications → Application Management → Show System.
- Select the desired service and click Disable (if the button is inactive – first click Remove Updates).
- Confirm the action and restart the phone.
How to check how much RAM the app eats?
- Open Settings → Applications → Application Management.
- Select the app and tap on the Memory.
- See the RAM Usage line (e.g. 450MB of 3GB).
Comparison of RAM consumption on Redmi 9 (3 GB of RAM):
| Annex | The usual version (MB) | Lite version (MB) |
|---|---|---|
| 600–800 | 150–200 | |
| 500–700 | 100–150 | |
| Messenger | 300–400 | 50–80 |
💡
If you can’t find the Lite version on Google Play, download APK from the official APKMirror website (like Facebook Lite). But before installing, turn off the source check in Settings → Security → Unknown Sources.
Method 5: Optimizing the Autoboot of Applications
Many apps run automatically when you turn on your phone or connect to the Internet, to fix this:
- Install App Inspector (free on Google Play).
- Open the application and go to the Autoboot tab.
- Turn off autoplay for unnecessary apps (such as games or stores).
Alternative method (without third-party applications):
- Go to Settings → Battery and Performance → Battery Management.
- Select the Applications Selection and set the Restricted mode for them.
Examples of applications that can be safely restricted:
- 🎮 Free Fire, Clash of Clans – They don’t need background mode).
- 🛒 Stores (AliExpress, Wildberries) – run manually only).
- 📺 Video services (YouTube, TikTok) cache content aggressively).
💡
Restricting autoboot reduces RAM consumption by 20-40% and increases battery life by 10-15%.
Method 6: Reset partition cache (without data loss)
If previous methods didn’t work, try resetting the /cache partition cache.This won’t delete your files, but will clear the temporary system data:
- Turn off the phone.
- Press the Power button + Volume up until the Mi logo appears.
- From the Recovery menu, select Wipe & Reset → Wipe Cache.
- Confirm the action and restart the phone.
This method helps if:
- 📉 The phone started to brake after the update MIUI.
- 🔄 Applications spontaneously close even with 1 GB of free RAM.
- 🛠️ B Settings → Memory shows that the cache is taking up >500MB.
⚠️ Warning: Do not confuse Wipe Cache with Wipe Data! The second option will erase all your data (photos, contacts, apps). → Google → Backup.
Method 7: Switching to custom firmware (for advanced)
If Redmi 9 And it's slowing down even after all the optimizations -- it's the firmware's fault. MIUI overloaded with unnecessary functions, and the shell consumes up to 1 GB RAM in the background. Solution is to install custom firmware based on Android. 12/13:
- 🔧 LineageOS – the most stable, but without the branded chips Xiaomi.
- 🚀 Pixel Experience – pure Android with features from Google Pixel.
- ⚡ Havoc-OS - customizable firmware with improved RAM management.
Installation instructions (briefly):
- Unlock the bootloader through the official Xiaomi tool.
- Install TWRP Recovery (Redmi 9 version is here).
- Download firmware (such as LineageOS) and GApps (mini-package).
- Flush through TWRP in order: firmware → GApps → Magisk (if root is needed).
Results after switching to LineageOS 20 (based on Redmi 9 user tests):
- 📈 Free RAM has become 30-50% more (from 1.2 GB to 1.8 GB at 3 GB of RAM).
- ⚡ Battery life increased by 15-20%.
- 🎮 Call of Duty Mobile games run without lags on medium settings.
⚠️ Attention: Installing custom firmware will void the warranty and may lead to a phone blink. If you are not sure of your abilities, contact a specialist.