Huge battery consumption on KDE

Used to buy new battery for my pretty old asus laptop.
But the battery life is horrible, 2h 50min of use with new battery.
So I did a powertop to locate what takes so much power in my system.

the most of the time “tick_sched_timer” and the two kwin_x11 processes take the most power.
How can I save my power usage in this situation?

When I plug the AC on my discharge rate drops to 8W and 6h of usage.
Why do battery mode consume more power?

Hi!
I use slimbookbattery, it’s let you disable almost everything on your laptop, like bluetooth,wifi,wlan,etc. And you can configure profiles for your power governor. Besides the app, I would recommend you to disable all services,effects you don’t use, and make the animations slower

1 Like

Hi!
The animations effects. You can set how fast or slow are the animations. Faster= more battery drain. Check settinggs/workspace

Ok and what about “tick_sched_timer” and the two kwin_x11 processes ?

Hi, my advice is to use TLP with it’s GUI (TLPUI). It’s a simple enough power management tool, it lets you decide power consumption when you’re plugged in or are using the battery, for example you can set the CPU to be in battery saving mode when not plugged in (a feature that I find very useful) and A LOT of other parameters!
Even with my not at all new battery I was able to get almost 5 hours of battery life from my ASUS laptop (at the expense of performance obviously, but it is good enough for what I do), while I was getting 2.5 hours like you before.
You can find information and instructions at this link: Power Management - Manjaro

3 Likes

Hi!
I imagine that you have some widgets how update themself so often, set the update interval bigger. And the 2 kwin process is because you have 2 virtual desktops.

1 Like

When I plug the AC on my discharge rate drops to 8W and 6h of usage.
Why do battery mode consume more power?

No idea on my side but looking at that screenshot the power-usage reported should be more like ~ 8.5W and not 18.4W… (Just manually add the numbers of power-usage)

What usually consumes more energy is brightness and graphics. So:

  • avoid effects, unless they really bring some experience improvement
  • avoid plasmoids
  • reduce brightness to a level in which you can still work when on battery
  • disable the boost clock and limit cpu clock to a fair maximum (depending on your needs)
  • usually, you can also limit the gpu clock

Many of these settings can be configured in TLP. Others require udev rules, for example, and others can be configured in KDE energy settings. There are also other options related to WiFi and disk activity which can be configured in TLP.

I can paste my laptop config later (I’m on my desktop now). I have my cpu and gpu clocks limited there, and it improved a lot my battery time. Of course I don’t use that machine for gaming. I mostly don’t miss the extra power when working (except when I need to do some image editing - processing is noticeably slower).

1 Like