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When a phone remains painfully slow immediately after a factory reset, the issue is almost always a low-level bottleneck: aggressive thermal throttling, hardware degradation (flash storage wear), background service loops, or OS-level configurations like swap-to-disk overhead.

Tools and methods to diagnose and trace poor performance on a Xiaomi device (HyperOS / MIUI) range from quick settings fixes to deep system profiling tools.

1. Quick Xiaomi-Specific Diagnostics & Fixes

Before diving into command-line profiling, check these common MIUI/HyperOS settings that frequently degrade performance on mid-range hardware:

• Disable "Memory Extension" (Virtual RAM):

  • Where: Settings → Additional Settings → Memory Extension → Set to Off.

  • Why: Virtual RAM uses internal storage (UFS/eMMC) as swap memory. Storage write speed is orders of magnitude slower than physical RAM. On a fresh reset, this feature often turns back on by default and throttles system responsiveness.

• Access the Hardware Diagnostic Menu (CIT):

  • How: Open the Phone dialer and type *#*#6484#*#* (or go to Settings → About Phone → Detailed info and specs → tap Kernel version 5 times).

  • Use: Tests onboard sensors, thermal sensors, and flash storage responsiveness.

2. On-Device Profiling Tools (Developer Options)

Enable Developer Options by going to Settings → About Phone and tapping OS Version / MIUI Version 7 times.

System Tracing (Perfetto Frontend)

Android includes a native system trace recorder built into the Developer Options.

• Where: Settings → Developer Options → System Tracing.

• How to use:

  1. Turn on Trace debuggable apps and select categories (CPU frequency, scheduling, memory, graphics).

  2. Tap Record trace.

  3. Reproduce the stutter/lag (e.g., opening settings, scrolling) for 10–15 seconds, then stop the trace.

• Analysis: Pull the .pftrace file from /data/misc/perfetto-traces/ using ADB or a file manager and open it on ui.perfetto.dev. It shows exact CPU frequencies, kernel context switches, and thread bottlenecks.

Profile HWUI Rendering

• Where: Settings → Developer Options → Profile HWUI Rendering → Choose On screen as bars.

• How it helps: Displays real-time rendering performance on your screen. Any bar spiking above the green line (16ms for 60Hz or 8.3ms for 120Hz) indicates a dropped frame and pinpoints whether lag is UI thread/GPU-bound.

3. Deep System Debugging via ADB (PC Connected)

Connecting your phone to a computer with adb installed provides the clearest picture of what is slowing the system down.

A. Spot CPU Hogs & Rogue Daemons

Check if a background service or corrupt system app is pinning the CPU in an infinite loop:

adb shell top -m 10 -s cpu

• Look at CPU consumption percentage while the phone is idling. If process names like system_server, surfaceflinger, or Xiaomi telemetry services stay constantly high (>20-30%), you've found the issue.

B. Inspect Memory Pressure & Throttling

adb shell dumpsys cpuinfo
adb shell dumpsys meminfo

• dumpsys cpuinfo shows average load over time.

• dumpsys meminfo shows how physical RAM is allocated and if the system is under heavy memory pressure (zRAM thrashing).

C. Check Thermal Throttling

If a thermal sensor is failing or reporting incorrect values, the kernel will cap CPU frequencies to minimum levels to prevent damage.

adb shell dumpsys thermal

• Inspect the thermal zones. If status is marked as MODERATE, SEVERE, or CRITICAL while the device feels cold to the touch, a hardware sensor glitch is forcing CPU throttling.

D. Capture System Logcat Errors

A system service continuously crashing and restarting in the background causes severe UI lag:

adb logcat *:E

• If error messages stream rapidly without stopping, identify the package name causing the log spam.

4. Hardware Storage Wear Checks

If a phone remains slow post-reset, degraded flash memory (high write wear causing slow I/O) is a prime candidate.

Via ADB, check flash health stats (if accessible by the kernel build):

adb shell cat /sys/class/block/mmcblk0/device/life_time
# or for UFS storage:
adb shell "cat /sys/kernel/debug/*.ufs/health" 2>/dev/null

• Value outputs like 0x01 indicate 0-10% life used. If it reads 0x0A (90-100% life used) or higher, the onboard flash storage is worn out and throttling disk writes.

To install ADB (Android Debug Bridge), you don't need to install full software like Android Studio—you just need Google's official SDK Platform-Tools package.

Choose your operating system below.

Windows

Method 1: Portable Binary (No installation required)

.\adb devices

Opening PowerShell inside the platform-tools folder. Source: DroidViews

Method 2: Package Manager (Automated System-Wide Installation)

If you use a Windows package manager, you can install ADB system-wide without manually managing ZIP archives or environment variables:

• Winget:

  DOS

  winget install Google.PlatformTools
  

• Chocolatey:

  DOS

  choco install adb
  

macOS

Method 1: Homebrew (Recommended)

If you have Homebrew installed, open Terminal and run:

brew install android-platform-tools

This installs adb globally, allowing you to run adb devices from any terminal directory.

Method 2: Manual Zip

1. Download SDK Platform-Tools for Mac from Google.

2. Extract the .zip to your preferred folder (e.g., ~/platform-tools).

3. Open Terminal, navigate to the directory:

   Bash

   cd ~/platform-tools
   

4. Run ADB using ./adb:

   Bash

   ./adb devices
   

Linux

Package Manager (Debian / Ubuntu / Fedora / Arch)

Most distributions package ADB in their official repositories:

• Debian / Ubuntu / Mint:

  Bash

  sudo apt update
  sudo apt install android-tools-adb android-tools-fastboot
  

• Fedora / RHEL:

  Bash

  sudo dnf install android-tools
  

• Arch Linux / Manjaro:

  Bash

  sudo pacman -S android-tools
  

Preparing Your Phone

To allow your computer to communicate with your phone via ADB:

1. On your Android device, go to Settings → About Phone and tap Build Number (or OS Version) 7 times to unlock Developer Options.

2. Go to Settings → System → Developer Options (or Additional Settings → Developer Options).

3. Toggle USB Debugging to On.

4. Connect the phone to your computer via USB.

5. When you run adb devices for the first time, check your phone screen and tap Always allow from this computer on the RSA authorization prompt.