I have a 6th gen Thinkpad X1 Carbon, and the thing runs HOT. Lately, I’ve attached my dual monitor setup to it, and have been running temperatures in the high 70’s - and sometimes up into the low 90’s(!)

CPU Repaste and Fan clean

As the laptop is nearing 5 years old, I pulled out the fan module and cleaned off the old thermal paste. To my surprise, it almost appeared as if there was no paste on the actual CPU and only around it. With some 90% rubbing alcohol, I cleaned it fully, reapplied some paste, and then blew out the fan to dislodge any dust that had accumulated.

After this, I saw temps peak at about 73 degrees under load. Nice.

Undervolt CPU

In addition to the repaste, I used intel-undervolt to bring the CPU down by -140mV

You can read about how to do this here: https://wiki.archlinux.org/title/Undervolting_CPU

Changing Picom Configuration

Adding two lines to my picom.conf changed my temperatures significantly as well:

backend = "xr_glx_hybrid"

This helps render in whichever hardware your computer has - if you are running a laptop without descreet graphics, this will solve much of the temperature issue on its own.

use-damage = true

I believe what happens with a compositor is that it redraws pixels all the time - however what this line does is stops that in it's tracks and only redraws what is necessary.

Results

I now see my peak temperatures around 70 degrees. A pretty big improvement of almost 20 degrees from the worst temps prior. Not bad for all of 10 minutes of research and work.