Laptops are bad at everything except portability. I like to use my laptop on battery power, without mains electricity occasionally but unfortunately, my built in Nvidia graphics chip keeps turning on, getting hot and using 12 Watts or more of power doing nothing (20 watts total). I cannot use the BIOS to turn off the NVIDIA GEFORCE GTX chip.
I used Linux Mint 20 and power consumption dropped to less than 8 Watts but Mint uses old vulnerable versions of applications like thunderbird etc. I tried the latest Ubuntu Mate but the lowest power consumption I could get was 12 Watts and there were many other bugs so I re-installed Ubuntu Mate 20.04 again and compiled my own Email client but I am left with the Nvidia power problem.
My best simple option is to use the nouveau open source graphic driver which drops to less than 12Watts doing nothing. Optimus-prime works for a while.
I tried Bumblebee, optimus-prime, Nvidia settings, removing all nvidia drivers, blacklisting nvidia and but unfortunately, the Ubuntu-mate sound system scans the PCI bus and activates the same nvidia graphics chip through some back door (HDMI scan?) and ignores the realtek and Intel HDA drivers even whilst I am only using Intel graphics!
install snd_hda_codec_hdmi /bin/false # Did not help
I had been able to start and stop the nvidia chip by starting and stopping pulseaudio and relying on ALSA audio but no modern web browser uses ALSA, only pulsaudio and after a kernel update, that pulseaudio on/off trick no longer works and the Sound Preferences applet only shows Intel HDA output in mono or Nvidia (despite removal and purge of all nvidia kernel modules) but neither works for sound output in a web browser but ALSA still works fine for normal audio application on my Mate desktop.
dmesg shows that the nvidia PCI sound chip is started and the GPU just gulps down energy forever
[ 4.209655] snd_hda_intel 0000:01:00.1: Disabling MSI
[ 4.209661] snd_hda_intel 0000:01:00.1: Handle vga_switcheroo audio client
[ 4.211293] thermal thermal_zone5: failed to read out thermal zone (-61)
[ 4.219751] iwlwifi 0000:08:00.0: Applying debug destination EXTERNAL_DRAM
[ 4.220081] iwlwifi 0000:08:00.0: Allocated 0x00400000 bytes for firmware monitor.
[ 4.228026] iwlwifi 0000:08:00.0: base HW address: a4:02:b9:6b:3f:41
[ 4.246050] Adding 23448572k swap on /dev/sda5. Priority:-2 extents:1 across:23448572k SSFS
[ 4.278856] input: HDA NVidia HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input11
[ 4.278899] input: HDA NVidia HDMI/DP,pcm=7 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input12
[ 4.278961] input: HDA NVidia HDMI/DP,pcm=8 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input13
[ 4.279022] input: HDA NVidia HDMI/DP,pcm=9 as /devices/pci0000:00/0000:00:01.0/0000:01:00.1/sound/card1/input14
[ 4.290042] ieee80211 phy0: Selected rate control algorithm 'iwl-mvm-rs'
00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Host Bridge/DRAM Registers (rev 07)
00:02.0 VGA compatible controller: Intel Corporation HD Graphics 530 (rev 06)
00:1f.3 Audio device: Intel Corporation 100 Series/C230 Series Chipset Family HD Audio Controller (rev 31)
01:00.0 3D controller: NVIDIA Corporation GM107M [GeForce GTX 960M] (rev a2)
01:00.1 Audio device: NVIDIA Corporation GM107 High Definition Audio Controller [GeForce 940MX] (rev a1)
07:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS522A PCI Express Card Reader (rev 01)
With a fresh install and optimus and low power settings, I can get on battery usage down to 5 Watts but something always gets broken after updates.
My simple question is: is it not possible to turn off my Nvidia graphics chip in some simple repeatable quick death ?