apt-install cpufrequtils

add /etc/default/cpufrequtils :

ENABLE="true"
#GOVERNOR="ondemand",MAX_SPEED="0"
GOVERNOR="performance"

Script from ubuntu to check and set cpugov:

#!/bin/sh
echo "gov - show or set governor (set requires root privileges)"
echo "usage: [sudo] gov [o|ondemand|f|performance|p|powersave|c|conservative]"
echo "governor in use:"

getgov=$(cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor)

case $1 in
  o|ondemand)     governor=ondemand;;
  f|performance)  governor=performance;;
  p|powersave)    governor=powersave;;
  c|conservative) governor=conservative;;
  *)         echo $getgov     
  exit;;
esac

for g in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do echo $governor > $g; done
echo $(cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor)