So I'm new to Manjaro, however I've managed to set optimus under Ubuntu-based systems so i know it's possible with my setup.
My laptop has Nvidia MX250 as its GPU, as well as an Intel GPU.
mhwd -a nonfree 0300 automatically installed the following driver:
hybrid-video-intel-nvidia-440x-prime. After some investigation, I found out that this driver supports Nvidia's proprietary GPU offloading solution, as well as turning off the GPU when inactive. However, this feature is said to only work on Coffee Lake+ CPU's and Turing architecture GPU's.
While I do have a Coffee Lake CPU, my video card is one of the very last cards to still use Pascal architecture. Therefore, I concluded that the driver recommended by Manjaro does not disable the Nvidia GPU when not in use.
This is confirmed by my powertop output, i think (i'm new to powertop, i find it weird that everything shows up as 100%, however I have read that when the Nvidia GPU is not active, it should not show up at all in powertop):
Power est. Usage Device name 12.3 W 44,2% CPU misc 635 mW 44,2% CPU core 374 mW 44,2% DRAM 0 mW 68,3% Display backlight 100,0% USB device: xHCI Host Controller 100,0% USB device: ROG STRIX IMPACT (ASUS) 100,0% Radio device: iwlwifi 100,0% Radio device: btusb 100,0% PCI Device: Intel Corporation Cannon Point-LP SATA Controller [AHCI Mode] 100,0% PCI Device: NVIDIA Corporation GP108M [GeForce MX250] 100,0% PCI Device: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor The 100,0% PCI Device: Intel Corporation Coffee Lake HOST and DRAM Controller 100,0% PCI Device: Intel Corporation Cannon Point-LP PCI Express Root Port #13 100,0% PCI Device: Intel Corporation Cannon Point-LP PCI Express Root Port #5 100,0% PCI Device: Intel Corporation Cannon Point-LP CNVi [Wireless-AC] 100,0% PCI Device: Sandisk Corp Device 5004 100,0% PCI Device: Intel Corporation UHD Graphics 620 (Whiskey Lake) 100,0% PCI Device: Intel Corporation Cannon Point-LP USB 3.1 xHCI Controller 100,0% PCI Device: Intel Corporation Cannon Point-LP Thermal Controller 0,0% PCI Device: Intel Corporation Cannon Point-LP SMBus Controller 0,0% PCI Device: Realtek Semiconductor Co., Ltd. RTL810xE PCI Express Fast Ethernet cont 0,0 pkts/s Network interface: wlo1 (iwlwifi) 0,0 pkts/s Network interface: enp3s0 (r8169)
Therefore, I figured the default configuration proposed by mhwd is not adqeuate for my setup, and started looking for alternative solutions.
First, I looked into optimus-manager, as that seems to be the most well supported option.
However, none of the power management configurations seemed to work.
Either I couldn't switch to the nvidia card at all, i'd get a blackscreen when switching, or it would switch, but it wouldn't power down the nvidia card when switching back to Intel. (I did not try the acpi one, however).
Question: Should I have uninstalled
video-hybrid-intel-nvidia-440xx-prime and installed video-nvidia-440xx and xf86-video-intel when using optimus-manager? I did not find anything about this in the documentation, so I figured it would be best if i stuck with what mhwd recommended.
I then installed nvidia-switch and, while it did work (i did uninstall video-...-prime and installed nvidia-440xx and xf86-video-intel here, since it was specified as such in the documentation), I got a lot of graphical screen glitches when using intel mode (screen tearing, freezing when using full-screen applications) which were not fixed by archwiki's recommendations on screen tearing using xf86-video-intel. Additionally, the having to reboot aspect was not to my liking.
I'm now looking into nvidia-xrun, however it is not clear to me whether it would help me achieve my goal of having the nvidia videocard completely turned off when not in use. I'm doing all of this for battery saving purposes.
Do i need to remove hybrid-video-intel-nvidia-440xx-prime and install xf86-video-intel and video-nvidia-440xx when trying any other optimus management solution? I can't find much info anywhere.