How to set "Performance" instead of "Powersave" as default?

Performance and Powersave Governor Policies

There are various options for setting CPU governor policy described in Ask Ubuntu and other websites:

• How to permanently set CPU power management to the powersave governor?
• Prevent your laptop from overheating
• How I can disable CPU frequency scaling and set the system to performance?
• CPU Frequency scaling in Linux
• Avoiding CPU Speed Scaling – Running CPU At Full Speed

Keep in mind most websites suggest leaving CPU governing at Powersave. I'm on a laptop and found using Intel's ThermalD and P-State technologies coupled with TLP power management has best result for frequencies, fan speed and temperature.

Summarizing above links

To summarize achieving your goal from the above answers use:

Install cpufrequtils:

sudo apt-get install cpufrequtils

Then edit the following file (if it doesn't exist, create it):

sudo nano /etc/default/cpufrequtils

And add the following line to it:

GOVERNOR="performance"

Save and exit.

For changes take effect, run:

sudo systemctl restart cpufrequtils

Then you can run cpufreq-info to see informations about your cpu frequency, governor and more:

$ cpufreq-info
    current policy: frequency should be within 800 MHz and 3.90 GHz.
              The governor "performance" may decide which speed to use
              within this range.

As per this Q&A: Set CPU governor to performance in 18.04

If you want performance governor all the time you need to edit /etc/rc.local and insert these lines before the last line containing exit 0:

sleep 120 # Give CPU startup routines time to settle.
cpupower frequency-set --governor performance

To setup /etc/rc.local in 18.04 see: How to Enable /etc/rc.local with Systemd

I cannot comment because I have low reputation but I want to add the accepted answer. You will also need to run

sudo /etc/init.d/cpufrequtils restart

for this to take effect on your system. You should then see your frequencies hovering around the max listed and

current policy: frequency should be within 800 MHz and 3.90 GHz.
              The governor "performance" may decide which speed to use
              within this range.

When you type cpufreq-info

I'm on Xubuntu 18.04.02 LTS and installing cpufrequtils by sudo apt-get install cpufrequtils, made it possible to reduce the max CPU-speed. A nice option to have as the fan has stopped working.

After looking at the info by cpufreq-info, I created a file by sudo nano /etc/default/cpufrequtils, and wrote into it as in picture below. I found out it was of use to also set a value for min speed.

Lastly the command to make the change take action sudo /etc/init.d/cpufrequtils restart, resulting in this output from cpufreq-info:

To be clear - this is off course not my own findings, only a result of conclusions made from other earlier questions, comments, and answers on this forum. Especially the answer in this very question from WinEunuuchs2Unix.