3 Replies Latest reply on Dec 23, 2015 1:42 PM by EstebanC_Intel

    How to measure current hardware frequency


      I have been performing some experiments to understand the power distribution between CPU and GPU power planes while applying RAPL power limit. I see that the power usage in both these power planes get throttled to stay within the power limit.


      But I wanted to measure the frequency at which CPUs and GPU are running. The operating system (Linux in my case) does not expose the current operating frequency. The sysfs location given below only reports the system set frequency but it does not report the current hardware frequency.


      CPU: /sys/devices/system/cpu/cpu*/cpufreq/scaling_setspeed

      GPU: /sys/class/drm/card0/gt_cur_freq_mhz

      How do I measure the current hardware frequency for both CPUs and GPU - Are there any MSRs exposing these values?