cpufreq-setup-PE

#!/bin/bash

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

# Check availability :
if [ cpufreq-set ]
then
	echo ""
else
	echo -e "${RED} [ERROR] cpufreq-set not found. Try installing... ${NC} \n"
	echo "`sudo apt install cpufrequtils`"
fi

# Count CPUs :
MAX_CPU=$((`nproc --all` - 1))
CPU_FOUND=$((MAX_CPU + 1))
echo -e "${YELLOW} [INFO] Found ${CPU_FOUND} CPUs.\n"
#
# I discovered that AMD Ryzen 7840H CPU has a fixed 
# frequency at 544Mhz for both Min/Max to be stable.
#
# Meanwhile, most Intel since gen 6th can scale-down
# to exactly 400Mhz - which is great.
#
MIN="400Mhz" 

#
# And the maximum clock of my old lappy, which made me
# feel comfortable was only clocked at 3.2GHz.
#
# We can resemble modern Intel with P+E architecture 
# by using only 2P-cores + rest as E-cores.
#
P_MAX="3200Mhz"

# Let's check for customization :
# > cpufreq-setup-PE MIN P_MAX
if [ $# -eq 2 ]
then
	MIN="$1Mhz"
	P_MAX="$2Mhz"
fi
# Here is how it happens :
# > Set 2 first cores[0+1] as "P-core" within P_MAX range [400~3200]Mhz if no user-input. 
# > Set the rest of cores to MIN range [400~400]Mhz.
# 
for i in $(seq 0 $MAX_CPU); do
  [[ $i -lt 1 ]] && MAX_OPTION=$P_MAX || MAX_OPTION=$MIN
  echo -e "${GREEN} [cpufreq-set]: CPU #" $i " >> [" $MIN "~" $MAX_OPTION "]${NC}";
	sudo cpufreq-set -c $i --min $MIN --max $MAX_OPTION;
done