Software Tuning, Performance Optimization & Platform Monitoring
Discussion around monitoring and software tuning methodologies, Performance Monitoring Unit (PMU) of Intel microprocessors, and platform monitoring
Announcements
Welcome to the Intel Community. If you get an answer you like, please mark it as an Accepted Solution to help others. Thank you!

CPU Frequency Changing for Intel CPU

Kevin
Beginner
562 Views

Hi all,

I got a question when I changed the Intel CPU frequency for applications performance. When I changed the CPU frequency by 'cpupower'(which is a command line tool to change the cpu frequency) from 2300MHz(which is the maximum frequency in the Intel CPU) to 2301MHz, the execution time and power consumption of an application are totally different. The power consumption of frequency setting 2301MHz is 1.5 times than 2300MHz and the execution time is around 1.2 times than it. 

My question is: What's the meaning from changing a Intel CPU frequency from 2300MHz to 2301MHz(in this case)? Does that mean the 1MHz is specific to change the voltage/power capping/CPU mode/any other changes in Intel CPU?

Application
core frequency Exe time(s) Energy(J) Average power (w)
2300MHz 20.0 2916 146
2301MHz 16.7 3648 218

I am really appreciated if someone can help me.

Thank you so much! 

 

Regards,

Kevin

 

0 Kudos
1 Solution
McCalpinJohn
Black Belt
562 Views

The notation that adds "01" MHz is commonly used in CPU frequency utilities to to mean "request the maximum possible Turbo frequency".

Depending on your processor and system and BIOS and OS and whatever else is running on the system, the maximum Turbo frequency could be quite a bit higher than the 2300 MHz "base" frequency.   

As an example, the Intel Core i5-6350HQ has a nominal frequency of 2.3 GHz, but a maximum Turbo frequency of 3.2 GHz.   This could easily account for the reduced run time and increased power consumption in your results.

View solution in original post

2 Replies
McCalpinJohn
Black Belt
563 Views

The notation that adds "01" MHz is commonly used in CPU frequency utilities to to mean "request the maximum possible Turbo frequency".

Depending on your processor and system and BIOS and OS and whatever else is running on the system, the maximum Turbo frequency could be quite a bit higher than the 2300 MHz "base" frequency.   

As an example, the Intel Core i5-6350HQ has a nominal frequency of 2.3 GHz, but a maximum Turbo frequency of 3.2 GHz.   This could easily account for the reduced run time and increased power consumption in your results.

View solution in original post

Kevin
Beginner
562 Views

Hi John,

Got it. Thank you so much for your quickly reply. 

Regards,

Kevin

Reply