Brightness - ACPI or Xrandr - Which is good?

Technical issues/questions of an intermediate or advanced nature.
Testuser
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Brightness - ACPI or Xrandr - Which is good?

Post#1 by Testuser » 06 Feb 2022, 09:30

Hi Team,

Just one query.

Regarding brightness control.

On Internet I found the difference but not sure.

ACPI - Hardware based brightness control - so power consumption is reduced.

Xrandr - Software based. Might not reduce power consumption.

Please advise with your thoughts. :oops: :roll: :%)

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Rava
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Brightness - ACPI or Xrandr - Which is good?

Post#2 by Rava » 15 Feb 2022, 03:23

Testuser wrote:
06 Feb 2022, 09:30
ACPI - Hardware based brightness control - so power consumption is reduced.

Xrandr - Software based. Might not reduce power consumption.
With the internal notebook's or sub-notebook's display I either use the XFCE system tray slider (but I have no clue what XFCE uses in the background), or a xrandr based script.
At least all external monitors I know and use only the monitor's own brightness control works.
Testuser wrote:
06 Feb 2022, 09:30
power consumption is reduced.
[…] Might not reduce power consumption.
Would be good to get exact findings on that. Does anyone know an article on the issue?
Cheers!
Yours Rava

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Distribution: Porteus-v5.0-64-LXDE

Brightness - ACPI or Xrandr - Which is good?

Post#3 by Testuser » 27 Feb 2022, 10:56

Hi Rava,

Here is what I found.

https://wiki.archlinux.org/title/backlight.

For me xbacklight not workiing in Desktop, only working in laptop.

Xrandr - working on both desktops and laptop, So I beleive it is software based brightness control ( not actually reducing the brightness, this increases the blackness on the display - this is what I read in one of the forum in internet, now not able to find that link).

Anyway, I have posted a simple bright changer app for laptops using xbacklight and acpi.

This one uses yad program included in the package.

:)

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