So, if I understand what's happening here. When switching to Intel, both Nouveau and the proprietary driver are blacklisted and the power management is disabled because of "nouveau.run-pm=0" kernel parameter. The discrete GPU is therefore always ON, but cannot be used at all.
Why not just blacklist the proprietary driver to let Nouveau take care of the power management? It would also be great, if possible, to add "nvidia-drm.modeset=1" kernel parameter to enable prime synchronisation to avoid tearing. -- 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