Display running frequency of Raspberry Pi in command line

To display cpu's maximum, mimimum and current frequency, we can use the command:

• $ cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq
• $ cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq
• $ sudo cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
  (need permission)

Display CPU frequency of Raspberry Pi

We can also use vcgencmd command

• $ vcgencmd measure_clock arm
  to display ARM processor's clock speed. IT will be something like:
  frequency(45)=700000000
  means 700,000,000 Hz or 700MHz
• $ vcgencmd measure_clock core
  to display system's core frequency, like:
  frequency(1)=250000000
  250,000,000 Hz, or 250MHz.

Display clock speed with vcgencmd command

For more RPI vcgencmd usage, refer http://elinux.org/RPI_vcgencmd_usage