Upgraded to Kubuntu 15.04 and with that came nvidia 346.59 ( 346.59-0ubuntu1 )
$ uname -a Linux redacted 3.19.0-16-generic #16-Ubuntu SMP Thu Apr 30 16:09:58 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux $ dpkg --list | grep 346.59 ii libcuda1-346 346.59-0ubuntu1 amd64 NVIDIA CUDA runtime library ii libxnvctrl0 346.59-0ubuntu1 amd64 NV-CONTROL X extension (runtime library) ii nvidia-346 346.59-0ubuntu1 amd64 NVIDIA binary driver - version 346.59 ii nvidia-opencl-icd-346 346.59-0ubuntu1 amd64 NVIDIA OpenCL ICD ii nvidia-settings 346.59-0ubuntu1 amd64 Tool for configuring the NVIDIA graphics driver You can specify which GPU to use with the program nvidia-settings. Using: the GPU "PRIME Profiles" set for "Intel (Power Saving Mode)" which sets: $cat /proc/acpi/bbswitch 0000:01:00.0 OFF After a few days of this setting I can report that the issue of the dimming screen and random lock-ups seems to have disappeared. ---- I've just now run nvidia-settings to change back to use the GPU that's labeled "NVIDIA (Performance Mode)" and will update in later if this also no-longer has the issue. Tentatively reporting as fixed pending further testing . -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1405489 Title: [HP ZBook 15 Mobile Workstation] Ubuntu 14.10 random freeze and lock up with NVIDIA To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers-331/+bug/1405489/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs