How to use the command cpufreq-aperf (with examples)

The cpufreq-aperf command is used to calculate the average CPU frequency over a specified time period. It requires root privileges to run and provides information about the CPU frequency. It can be useful for monitoring system performance and analyzing CPU usage patterns.

Use case 1: Start calculating average CPU frequency

Code:

sudo cpufreq-aperf

Motivation: This command calculates the average CPU frequency for all CPU cores with a default 1-second refresh interval. It can be used to get an overall picture of the CPU usage on the system.

Explanation: The command “sudo cpufreq-aperf” starts calculating the average CPU frequency for all CPU cores. It runs with root privileges to access the necessary system information. By default, it refreshes the data every 1 second.

Example output:

Average CPU frequency: 2.4 GHz

Use case 2: Start calculating average CPU frequency for a specific CPU core

Code:

sudo cpufreq-aperf -c 1

Motivation: This command allows calculating the average CPU frequency for a specific CPU core. It can be useful when analyzing the performance of individual cores or troubleshooting issues related to a particular core.

Explanation: The command “sudo cpufreq-aperf -c 1” starts calculating the average CPU frequency for CPU core number 1. By specifying the option “-c 1”, the command focuses on a specific core instead of all cores. This can provide more detailed information about the behavior of individual cores.

Example output:

Average CPU frequency for CPU 1: 2.6 GHz

Use case 3: Start calculating average CPU frequency with a specific refresh interval

Code:

sudo cpufreq-aperf -i 3

Motivation: This command allows adjusting the refresh interval for calculating the average CPU frequency. A longer refresh interval can be useful when analyzing long-term CPU usage patterns.

Explanation: The command “sudo cpufreq-aperf -i 3” starts calculating the average CPU frequency for all CPU cores with a refresh interval of 3 seconds. By specifying the option “-i 3”, the command adjusts the refresh interval to 3 seconds instead of the default 1 second.

Example output:

Average CPU frequency (3-second interval): 2.3 GHz

Use case 4: Calculate the average CPU frequency only once

Code:

sudo cpufreq-aperf -o

Motivation: This command calculates the average CPU frequency only once, providing a snapshot of the current CPU performance. It can be useful when you only want to get a single measurement instead of continuous monitoring.

Explanation: The command “sudo cpufreq-aperf -o” calculates the average CPU frequency once and then exits. It does not refresh the data continuously like the other use cases. This can be helpful when you need to quickly check the current CPU frequency without ongoing monitoring.

Example output:

Average CPU frequency: 2.3 GHz

Conclusion:

The cpufreq-aperf command provides a flexible way to calculate the average CPU frequency and monitor system performance. By using different options, you can focus on specific CPU cores, adjust the refresh interval, or get a single measurement. With this command, you can gain insights into the CPU usage patterns and analyze the behavior of individual cores.