Throttle CPU

A C program that monitors CPU temperature and automatically throttles CPU frequency to prevent overheating on Linux systems.

Description

This program continuously monitors the CPU temperature and automatically reduces the CPU frequency when the temperature exceeds a user-defined limit.

Features

• Real-time CPU temperature monitoring
• Automatic CPU frequency throttling
• Multiple throttling attempts with configurable parameters
• Graceful restoration of original CPU frequencies
• Support for multi-core processors
• Signal handling for clean program termination

Prerequisites

• Linux operating system
• GCC compiler
• Root privileges (required for CPU frequency control)
• Access to system files:
  • /sys/class/thermal/thermal_zone0/temp
  • /sys/devices/system/cpu/cpu*/cpufreq/

Installation

1. Clone the repository or download the source code
2. Compile the program:

   gcc throttle_cpu.c -o throttle_cpu

Usage

Run the program with root privileges and specify the temperature limit in Celsius:

Usage: sudo ./throttle_cpu <Temperature_Limit> <Max_Attempts> <Wait_Time_After_Throttle>
Arguments:
  Temperature_Limit            : Maximum CPU temperature before throttling (1–110°C)
  Max_Attempts                 : Number of times the program will attempt to throttle (default: 5)
  Wait_Time_After_Throttle     : Wait time between throttle attempts, in seconds (default: 15)

Example:

sudo ./throttle_cpu 80    # Sets temperature limit to 80°C

Configuration Constants

The program includes few fixed parameters(change them if you want):

#define FREQUENCY_DECREMENT 500000      // Frequency reduction step (Hz)
#define WAIT_TIME_AFTER_TEMP_DROP 3000  // Wait time after temperature drops (seconds)

How It Works

1. The program reads the current CPU temperature from the system
2. If the temperature exceeds the specified limit:
   • Reduces the maximum frequency for all CPU cores
   • Waits for a specified time period
   • Checks the temperature again
3. If the temperature is still high after maximum attempts:
   • Restores original frequencies
   • Exits the program
4. Handles Ctrl+C (SIGINT) gracefully by restoring original frequencies

Error Handling

The program includes comprehensive error handling for:

• File operations
• Temperature and frequency reading/writing
• Invalid user input
• System calls

Demo GIF

Notes

• Requires root privileges due to system file access
• Temperature readings are in Celsius
• Frequency values are in Hertz
• The program continuously monitors temperature until interrupted
• Use Ctrl+C to safely exit and restore original frequencies

License

This project is open source and available under the MIT License.