Public bug reported: This is the same issue as originally reported in bug 1765363 but that report is old and has a lot of extra data on it so it was requested that a new bug be opened if we were still having the issue.
So... I am still having the issue, at least with the 390 series drivers (my laptop has a Quadro 5400M). Switching to Intel mode via either the GUI in nvidia-settings or via prime-select successfully moves the rendering to the Intel card but does not power down the discrete card, as evidenced by either power consumption in powertop in excess of 20W, or by manually checking /proc/acpi/bbswitch (shows ON). Manually echoing off into /proc/acpi/bbswitch does turn the card off as can be seen from the power consumption drop. ProblemType: Bug DistroRelease: Ubuntu 20.10 Package: nvidia-prime 0.8.15 ProcVersionSignature: Ubuntu 5.8.0-40.45-generic 5.8.18 Uname: Linux 5.8.0-40-generic x86_64 ApportVersion: 2.20.11-0ubuntu50.3 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Sun Jan 24 19:07:10 2021 Dependencies: InstallationDate: Installed on 2021-01-24 (0 days ago) InstallationMedia: Ubuntu 20.10 "Groovy Gorilla" - Release amd64 (20201022) PackageArchitecture: all ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: nvidia-prime UpgradeStatus: No upgrade log present (probably fresh install) ** Affects: nvidia-prime (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug groovy -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1912974 Title: discrete card not powered down in Intel mode with legacy drivers To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nvidia-prime/+bug/1912974/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs