Ubuntu – What do you do when Nvidia-CUDA drivers break Ubuntu

I was having exactly the same problem with nvidia-346 and kernel 3.13.0-45 on Ubuntu 14.04 amd64. After too many hours of searching and experimentation, I managed to fix it. I explain the whole problem along with a solution in detail here: http://vxlabs.com/2015/02/05/solving-the-ubuntu-14-04-nvidia-346-nvidia-prime-black-screen-issue/

In short, try the following:

• Switch to console (Ctrl-Alt-F1) and stop lightdm: sudo service lightdm stop

• Disable gpu-manager by commenting out everything in /etc/init/gpu-manager.conf

• Switch to nvidia mode by doing sudo prime-select nvidia

• Change your /etc/X11/xorg.conf to look like the one at the bottom of this answer, making sure that the nvidia BusId is correct (check with lspci):

• Start X up again with sudo lightdm start

If after this you still get a black screen, please double-check that your xorg.conf has not been reset to the configuration without modesetting. If so, make sure that lightdm has been stopped and gpu-manager disabled before you edit the xorg.conf to change the intel driver to modesetting.

Switching back to Intel you will have to stop lightdm, re-enable gpu-manager, activate intel mode with sudo prime-select intel and then restart X with sudo service lightdm start.

It's very possible that later versions of gpu-manager might have fixed this behaviour.

Here's the correct xorg.conf:

Section "ServerLayout"
  Identifier "layout"
  Screen 0 "nvidia"
  Inactive "intel"
EndSection

Section "Device"
  Identifier "intel"
  Driver "modesetting"
EndSection

Section "Screen"
  Identifier "intel"
 Device "intel"
EndSection

Section "Device"
  Identifier "nvidia"
  Driver "nvidia"
  BusID "PCI:1:0:0"
EndSection

Section "Screen"
  Identifier "nvidia"
  Device "nvidia"
  Option "UseDisplayDevice" "None"
EndSection

The problem is that Nvidia driver cannot be correctly used by X Server. Uninstall everything like nvidia-*, it may help you solve the problem without reinstall the system, but I strongly suggest you to reinstall it if you are not an expert at Linux (I am not, so I have reinstalled several times my laptop in order to work with Cuda)

I have recently installed Cuda on my MSI GS60 (HD4600 + GTX860M + Ubuntu 14.04), I think my solution should work for you.

If you want to install Cuda while keeping Intel for display, my solution is for you. PS: it is not really my solution, but the solution on the official documentation, with more details:

• Make sure you have a iXXX (i915 in my case) for Intel
• Block nouveau device if you have
• Download the runfile and set the correct access policy
• Reboot into runlevel 3 (while choosing the system to boot, edit the boot info (tap E usually), replace "quiet splash" with "text", continue)
• Run the runfile with "--no-opengl-libs"
• Reboot normally

I hope it will help you.