high cpu use (idle) on new asus tuf fx505dy
 

Hello :-) First laptop, and concerned at idle cpu use, and how relates to bad battery life. Wifi/vpn active, AC plugged in or not, notes and clock widget, and one small text file ... constant spikes of high use, 10-25%+ of cpu, and up to 60%+ at times ... 12% often seen during changes. On main desktop (arch/lts kernel/kde), idle cpu use very low indeed, 0-2%.

Arch (beginner), latest kernel (having to run so can boot; prefer lts), kde. Asus tuf fx505dy, ryzen 5/vega 8 (and unuseable RX560!), bios 304.

EDIT: looking for ways to increase performance, saw about turning off mitigations, so, incase helpful to anyone new to this, I did
sudo nano /etc/default/grub
and
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash mitigations=off"
then regenerated grub.cfg ...
grub-mkconfig -o /boot/grub/grub.cfg

CPU now showing 0% on idle. Battery (full) shot up to showing 10 hrs battery left, then dropped back to the usual 2, grrr. But then moves to 3.33 hrs, which is the best so far, then back to 2.15/2 etc.

sounds like you need to explore and find out what is using so much CPU. my last heavy CPU usage was cause by Firefox visiting a badly programmed web site. it managed to reach 366% (of 4 cores). the "top" command in a terminal shell might be useful.

Sorry, I don't seem to be getting notifications, but just saw your response, and, wow, 366% must be some kind of record! :-) Thanks for advice too. Will keep an eye on things.

The command line programs top or htop should help you identify what processes are using your CPU cycles.

See man top or man htop for more.

Thank you frankbell. Will definitely take a look at those packages. :-)

I am very interested by this thread. I face a similar problem, which is, an indexing process for a search process that I really love (the 'Recoll' utility) seems to take all CPU when the machine is idle, even when on batteries.

What I would like is to detect the switch to battery power, then issue some kill -STOP command to Recoll (automatically identifying its process #) and when back on the mains switch back with a kill -CONT...

Needless to say I don't know how to deal with this, nor even if this is the right way to do...

TIA!
H.

Have a look at the Arch linux wiki page on power management. Suspend/resume might become interesting.
Just kill it and restart in your scripts. Untested - I always disable any indexers.