PowerTOP – diagnose issues with power consumption and power management on Linux
Power management in Linux is a bit wacky still.<p>I was running a super ancient Linux distro on this laptop for years, and had two weird incidents. In one, I was trying to tweak power settings manually, and somehow got the CPU fan stuck on &quot;full-speed&quot; for something like 6 months. Then later I installed either PowerTOP or TLP or some other tool I don&#x27;t know, and it recalibrated my power settings.... immediately the fan stopped going full-speed, and it would only turn on when the CPU was really chugging.<p>Fast forward to today, I upgraded to Ubuntu 20.04. Just letting the machine idle after boot-up runs the CPU fan continuously at low speed. Opening a browser sends it into full-speed mode until I close the browser (virtually any page). But it&#x27;s the same machine, and same version of Firefox. So, something about this newer kernel + OS has resulted in the fan spinning way more than the old kernel + OS. Trying to figure out how or why leads you nowhere, because of course it&#x27;s all specific to your hardware and whatever in the kernel has changed.<p>Now you might think, &quot;OK, just turn on power-saving, the fans should be silenced.&quot; Nope. Tried every single power tweak that exists, and I can&#x27;t force the fans to quiet. I can make the CPU run dog slow, but the fans keep chugging. Which is really annoying when all you want is a few minutes of peace and quiet.