Fully Power Down Discrete GPU You may want to turn off the high-performance graphics processor to save battery power, this can be done by installing the acpi_call package. Tip: For kernels not in the Official repositories, the acpi_call-git-dkmsAUR is an alternative. See also DKMS. Once installed load the kernel module: # modprobe acpi_call With the kernel module loaded run the following: # /usr/share/acpi_call/examples/turn_off_gpu.sh This script will go through all the known data buses and attempt to turn them off. You will get an output similar to the following: Trying \_SB.PCI0.P0P1.VGA._OFF: failed Trying \_SB.PCI0.P0P2.VGA._OFF: failed Trying \_SB_.PCI0.OVGA.ATPX: failed Trying \_SB_.PCI0.OVGA.XTPX: failed Trying \_SB.PCI0.P0P3.PEGP._OFF: failed Trying \_SB.PCI0.P0P2.PEGP._OFF: failed Trying \_SB.PCI0.P0P1.PEGP._OFF: failed Trying \_SB.PCI0.MXR0.MXM0._OFF: failed Trying \_SB.PCI0.PEG1.GFX0._OFF: failed Trying \_SB.PCI0.PEG0.GFX0.DOFF: failed Trying \_SB.PCI0.PEG1.GFX0.DOFF: failed Trying \_SB.PCI0.PEG0.PEGP._OFF: works! Trying \_SB.PCI0.XVR0.Z01I.DGOF: failed Trying \_SB.PCI0.PEGR.GFX0._OFF: failed Trying \_SB.PCI0.PEG.VID._OFF: failed Trying \_SB.PCI0.PEG0.VID._OFF: failed Trying \_SB.PCI0.P0P2.DGPU._OFF: failed Trying \_SB.PCI0.P0P4.DGPU.DOFF: failed Trying \_SB.PCI0.IXVE.IGPU.DGOF: failed Trying \_SB.PCI0.RP00.VGA._PS3: failed Trying \_SB.PCI0.RP00.VGA.P3MO: failed Trying \_SB.PCI0.GFX0.DSM._T_0: failed Trying \_SB.PCI0.LPC.EC.PUBS._OFF: failed Trying \_SB.PCI0.P0P2.NVID._OFF: failed Trying \_SB.PCI0.P0P2.VGA.PX02: failed Trying \_SB_.PCI0.PEGP.DGFX._OFF: failed Trying \_SB_.PCI0.VGA.PX02: failed See the "works"? This means the script found a bus which your GPU sits on and it has now turned off the chip. To confirm this, your battery time remaining should have increased. Currently, the chip will turn back on with the next reboot to get around this we do the following: Note: To turn the GPU back on just reboot. Add the kernel module to the array of modules to load at boot: /etc/modules-load.d/acpi_call.conf #Load 'acpi_call.ko' at boot.
acpi_call To turn off the GPU at boot we could just run the above script but honestly that is not very elegant so instead lets make use of systemd's tmpfiles. /etc/tmpfiles.d/acpi_call.conf
w /proc/acpi/call - - - - \\_SB.PCI0.PEG0.PEGP._OFF The above config will be loaded at boot by systemd. What it does is write the specific OFF signal to the /proc/acpi/call file. Obviously, replace the \_SB.PCI0.PEG0.PEGP._OFF with the one which works on your system (please note that you need to escape the backslash).