How to speed up Xiaomi Redmi Note 9: a complete guide to optimization

Xiaomi Redmi Note 9 It is still one of the most popular budget smartphones due to its balanced characteristics: MediaTek Helio processor. G85, 4/6 GB RAM and battery per battery 5020 But over time, even this workhorse starts to slow down -- apps open for a long time, animations twitch, and the system hangs when multitasking, and the reasons can lie in clogged cache and suboptimal settings. MIUI or outdated firmware.

In this article, we will discuss 10 Proven ways to speed up the Redmi Note 9 — From basic (cleaning up memory, disabling animation) to advanced (overclocking the processor, flashing to custom software). All methods tested on current versions. MIUI 14/15 And it doesn't require root rights unless you say otherwise. Importantly, some tweaks can slightly reduce battery life -- we'll mark those moments separately.

1.Diagnostics of current performance

Before optimizing a smartphone, you need to understand what exactly is slowing it down. Redmi Note 9 has built-in diagnostic tools, as well as third-party utilities that will show “bottlenecks”.

Open the Settings. → The phone. → All specifications → System status. This is the mapping:

• 📊 RAM usage – if less than 1 GB is free at 4 GB of RAM or 1.5 GB at 6 GB, the system begins to “kill” background processes, which causes slowdowns.
• 🔋 Processor temperature – values above 50°C at normal load speak of thermal throttling (automatic frequency reduction due to overheating).
• 🗃️ Occupied storage – if less than 10% of the total volume is free (for example, less than 6 GB by 64 GB), this critically slows down the writing/reading of files.

For a detailed analysis, install the DevCheck app (free on Google Play) and it will show:

• 🔄 Real CPU frequency (should be close to 2.0 GHz in load).
• 📱 Version MIUI Android kernels (old firmware often contains bugs).
• 🔌 Battery condition (wearing above 25% can cause sudden reboots).

⚠️ Note: If DevCheck displays a CPU frequency below 1.0 GHz when you’re just loading (like surfing in your browser), this is a sign of active thermothrottle. In this case, first solve the problem with overheating (see section 5), otherwise any optimization will be temporary.

System cleanup: cache, debris and background processes

Clogged cache and unnecessary background processes are the main “brakes” for the Redmi Note 9.MIUI It tends to accumulate temporary files, especially if you use social networks, instant messengers or games a lot%.

Step 1. Clean up the app cache

1. Go to Settings → Applications → Application Management.
2. Slip on the three dots in the upper right corner and select Sort by size.
3. Open apps with a cache of more than 500MB (usually Facebook, Instagram, YouTube, Telegram) and click Clear Cache.

Step 2: Systemic debris disposal

• 🧹 Use the built-in utility: Security → Cleanup → Deep cleaning. It removes residual files, logs and unnecessary ones. APK.
• 🗑️ For advanced cleaning, install SD Maid (requires root for full functionality) The free version provides cleaning of the basket, empty folders and duplicates.

Step 3: Disabling Autoboot Applications

Many programs run when you turn on your smartphone and hang in the background, consuming RAM. To turn off autoboot:

1. Go to Settings → Applications → Application Management.
2. Select an app (such as AliExpress or TikTok) → Auto-start → turn off the slider.

Clean the cache of social networks and instant messengers

Remove unused apps (especially Xiaomi clones)

Turn off autostart for 10+ background

Perform a deep cleanup through "Safety"

Reboot the phone-->

⚠️ Note: Do not cache system applications like com.android.systemui or com.miui.home manually through the SD Maid, this can cause the launcher to crash. For them, only use the built-in cleaning in the launcher. MIUI.

3. MIUI Optimization: Hidden Settings and Tweaks

MIUI It contains dozens of hidden features that you can configure to speed up work, most of which don't require root rights, but some will require activation of the developer mode.

How to turn on the developer mode:

1. Go to Settings. → The phone.
2. Tap 7 times on the MIUI version (you will be notified “You became a developer”).
3. Back to Settings → Additionally. → For developers.

Top.-5 speed-up:

• ⚡ Disable animation: In For developers, find: The scale of the animation window → Animation disabled Transition animation scale → Animation disabled Duration of animator → Animation disabled Effect: Apps will open instantly, but the interface will become less smooth.
• 🔄 Background Process Limit: In For Developers, select the Background Process Limit → 2 process maximum. This will free up RAM, but some messengers will reboot more often.
• 🎯 GPU-Acceleration: Activate Forced Processing GPU and debugging GPU-This will speed up the rendering of the interface, but can increase battery consumption by 5-10%.

Additional settings MIUI:

• 🔕 Disabling Mi-services: Go to Settings → Notifications → Manage notifications and disable unnecessary system alerts (e.g. Mi Video, Mi Music, GetApps).
• 📶 Network optimization: In Settings → SIM-maps and mobile networks → Data transfer enable Smart Mode (automatically switches between 4G and 3G energy-saving).

Update of firmware: official and custom options

Outdated firmware is one of the main reasons for the brakes. Xiaomi regularly releases updates for the Redmi Note 9, fixing bugs and optimizing performance. MIUI It can be slow because of the heavy interface, and then it's very easy to switch to lightweight firmware.

Official update through OTA:

1. Go to Settings → About the phone → System update.
2. Click on the three dots in the top right corner and select Update Package (if available).
3. If the update does not come, download the latest version. MIUI for Redmi Note 9 (merlin) from the official Xiaomi website and install via System Update → Select a firmware file.

Alternative firmware (requires unlocking the bootloader):

It's important before the firmware:

• 🔐 Unlock the bootloader through the official Mi Unlock Tool (binding to the Xiaomi account is mandatory!).
• 📱 Make a backup through Settings → System system → Backup or TWRP.
• 🔋 The battery charge must be at least 60%.

💡

After the update MIUI The phone is getting hotter, rolling back to the previous version, or resetting to factory settings. New builds sometimes contain bugs related to power management of the Helio processor. G85.

5.Overheating: Why the Redmi Note 9 brakes when heated

MediaTek Helio G85 Redmi Note 9 is prone to overheating, especially during long loads (games, video, charging).°C is thermal throttling, and the processor automatically lowers the frequency, which leads to lags.

Programmatic methods:

• 🧊 Background Limitation: In Settings → Battery → Battery mode select Balanced or Saving Charge (reduces processor load).
• 🎮 Settings for games: In Settings → Special facilities → Game mode, turn on Restrictions FPS (For example, 45 instead of 60) and disable the improved graphics quality.
• 🔄 Turning off unnecessary cores (requires root): With Kernel Adiutor, turn off 2 cores out of 8 (e.g., cores 5-6) and leave 6 active. This will reduce heat output by 15-20%.

Hardware methods:

• 🛠️ Thermopaste replacement: Over time, the factory paste dries. Use high-temperature paste (e.g. Arctic) MX-6) and copper thermal gasket 0.5 mm thick for memory chips.
• 📱 Cooling cover: Aluminum cases (such as Black Shark Cooler) reduce temperature by 5-10°C.
• 🌬️ External cooler: Connected fans (e.g. Baseus Cooling Fan) are effective for long gaming sessions.

💡

If the Redmi Note 9 heats up even in a simple (for example, when watching a video), the problem may be in the discharged battery. < 80%) cause increased heat generation.

6.Memory Optimization: How to Free RAM and Storage

Redmi Note 9 was released with 4 or 6 GB of RAM. Over time, even 6 GB becomes scarce due to “gluttonous” applications.

Method 1: Forced release of RAM

• 🔄 Use the built-in function: Settings → The phone. → Memory. → Clean (releases up to 1-1.5 GB).
• 📱 Install the widget. RAM Booster (from GetApps) for quick cleaning with one tap.

Method 2: Transfer applications to a memory card

If you have a microSD (class recommended) A2 or UHS-I), Bring heavy applications to it:

1. Go to Settings → Applications → Application Management.
2. Select an app (such as Facebook) → Warehouse → Change. → Map. SD.

Method 3: Use of a swap file

If you have root rights, you can create a swap file on the memory card, which will be used as additional RAM:

su


dd if=/dev/zero of=/sdcard/swapfile bs=1M count=1024




mkswap /sdcard/swapfile




swapon /sdcard/swapfile

Warning: This is a temporary solution. The constant swap on the microSD reduces its lifespan.

7 Advanced methods: overclocking, cores and Magisk modules

If the standard methods didn't work, you can use advanced optimization, which requires unlocked bootloaders and root rights, but maximizes performance.

Method 1. Overclocking of the processor (undervolting) + OC)

With the help of the Magisk Kernelsu or FrancoKernel module, you can:

• ⚡ Increase the maximum frequency of Helio G85 2.0 to 2.2 GHz (gaming gains) ~10–15%).
• 🔋 Reduce voltage by 50–100 mV to reduce heat without loss of performance.

Recommended settings for Redmi Note 9:

# In file /sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq


echo 2200000 > /sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq



Undervolting (example for core 1)



echo "850000 750" > /sys/devices/system/cpu/cpufreq/policy0/uv_table

Method 2: Core optimization

Install a custom core, for example:

• 🔧 Perseus Kernel – Focuses on performance and battery savings.
• 🛡️ Neon Kernel – the best stability for daily use.

Installation via TWRP:

1. Download. ZIP-core XDA Developers.
2. Reboot to TWRP (Power + Vol Up).
3. Choose Install. → specify the kernel file → Swipe to confirm.

Method 3: Magisk modules for optimization

• 🚀 Universal GMS Doze – Aggressively optimizes Google Services background.
• 🗑️ App Systemizer – converts user applications into system (reduces RAM consumption).
• 🔄 Greenify4Magisk — Forcedly “freezes” unnecessary applications.

💡

Before installing a custom core or overclocking the processor, check its stability using the Prime95 or 3DMark. If tests show errors or reboots, reduce the frequency by 100 MHz.

8.Alternative launchers and lightweight applications

Interface. MIUI It's pretty heavy, especially with animations and widgets, and replacing the standard launcher and applications with lightweight ones can give you up to 20 percent of the speed%.

Top.-3 Fast launcher for Redmi Note 9:

• 🌟 Nova Launcher is minimalist, supports gestures and customization of icons. Customization: disable animations in Nova Settings → Look & Feel → Animation Speed → None.
• ⚡ Lawnchair 2 is based on Pixel Launcher, but without the unnecessary services of Google. MIUI Launcher at 30-40%.
• 📱 Smart Launcher 5 – automatically sorts applications by category, reducing the load on the processor when searching.

Facilitated alternatives to popular applications:

How to install lightweight applications:

1. Download. APK from official websites (e.g. NewPipe or Hermit).
2. In Settings → Applications → Special Access → Install unknown applications allow installation from your file manager.
3. Install. APK and disable auto-start for the original app.

⚠️ Note: Some light apps (such as Facebook Lite) may not support all of the original features. Check if you are comfortable with them before you fully transition.

FAQ: Frequent questions about the Redmi Note 9 acceleration