I tried something this morning, since I was convinced that this problem revolves around Nouveau power management.
I made a backup of prime-select, # cp /usr/bin/prime-select /usr/bin/prime-select.orig and replaced the parameter that disables Nouveau power management (as per https://nouveau.freedesktop.org/wiki/KernelModuleParameters/). # sed -i "s/boot_params\['nouveau.runpm'\] = '0'/boot_params\['nouveau.runpm'\] = '-1'/" /usr/bin/prime-select After restarting on the integrated GPU, I launched Powertop (sudo powertop) in a terminal to measure the power consumption at idle, and it was around 6W. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to nvidia-prime in Ubuntu. https://bugs.launchpad.net/bugs/1765363 Title: prime-select intel is not powering off the nvidia card Status in nvidia-prime package in Ubuntu: Confirmed Bug description: Right now, it seems that prime-select intel makes sure the nvidia driver is not loaded, as nvidia-settings reports. But my power consumption is > 20W. cat /proc/acpi/bbswitch reports the card is still on. If bbswitch and powertop are reliable, then the nvidia card is still powered. This is a thinkpad w520 in Optimus mode. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: nvidia-prime 0.8.7 ProcVersionSignature: Ubuntu 4.15.0-15.16-generic 4.15.15 Uname: Linux 4.15.0-15-generic x86_64 ApportVersion: 2.20.9-0ubuntu5 Architecture: amd64 CurrentDesktop: ubuntu:GNOME Date: Thu Apr 19 19:56:21 2018 Dependencies: EcryptfsInUse: Yes InstallationDate: Installed on 2017-12-14 (125 days ago) InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Release amd64 (20171018) PackageArchitecture: all SourcePackage: nvidia-prime UpgradeStatus: Upgraded to bionic on 2018-03-09 (41 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nvidia-prime/+bug/1765363/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
