Just came back to Solus after a little while on Arch. Glad to report that with a little tinkering, Nvidia seems to work fine on an optimus laptop complete with power management. So you can save power with the card off when not in use and power it up when needed for gaming without log out, nvidia-xrun or any other solutions.
I have an MSI GS66 with RTX2060 - I believe you need a recent Nvidia card for this to work.
From chapter 22 of the Nvidia setup guide:
mkdir /lib/udev/rules.d/ if it doesn't exist
nano /lib/udev/rules.d/80-nvidia-pm.rules
copy the following into nano and save with ctrl-x
Remove NVIDIA USB xHCI Host Controller devices, if present
ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x0c0330", ATTR{remove}="1"
Remove NVIDIA USB Type-C UCSI devices, if present
ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x0c8000", ATTR{remove}="1"
Remove NVIDIA Audio devices, if present
ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x040300", ATTR{remove}="1"
Enable runtime PM for NVIDIA VGA/3D controller devices on driver bind
ACTION=="bind", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x030000", TEST=="power/control", ATTR{power/control}="auto"
ACTION=="bind", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x030200", TEST=="power/control", ATTR{power/control}="auto"
Disable runtime PM for NVIDIA VGA/3D controller devices on driver unbind
ACTION=="unbind", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x030000", TEST=="power/control", ATTR{power/control}="on"
ACTION=="unbind", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x030200", TEST=="power/control", ATTR{power/control}="on"
echo "options nvidia "NVreg_DynamicPowerManagement=0x02"" > /etc/modprobe.d/nvidia.conf
nano /etc/X11/xorg.conf
copy the following into nano and ctrl-x to save:
Section "ServerLayout"
Identifier "layout"
Screen 0 "iGPU"
Option "AllowNVIDIAGPUScreens"
EndSection
Section "Device"
Identifier "iGPU"
Driver "modesetting"
EndSection
Section "Screen"
Identifier "iGPU"
Device "iGPU"
EndSection
Section "Device"
Identifier "dGPU"
Driver "nvidia"
EndSection
echo nouveau.modeset=0 | sudo tee /etc/kernel/cmdline
sudo clr-boot-manager update
Reboot and hopefully, should work fine. X will run with the intel card and power down the Nvidia card.
Hope this work for someone else as well. Good luck.
