Display Power management time setting Arch

, screenSetting up DPMS in X

Add the following to your /etc/X11/xorg.conf in the Monitor section:

Option "DPMS" "true"

Note: As of Xorg 1.8 DPMS is auto detected and enabled if ACPI is also enabled at kernel runtime

Add the following to the ServerLayout section, change the times (in minutes) as necessary:

Option "StandbyTime" "10"
Option "SuspendTime" "20"
Option "OffTime" "30"


Or

Option         "BlankTime" "30"

bron: https://wiki.archlinux.org/index.php/Display_Power_Management_Signaling