I have a ASUS G501JW laptop which sports the 960M.
I installed Ubuntu 15.04 and under Additional Drivers chose Nvidia binaries (346.59).
This all worked very well, until I plug in an external monitor via miniDisplayPort.
When I log in with this configuration, both screens start switching between being black and show some text (very briefly, no time to read it, but I can see some text with a green [OK] it keeps switching like this over and over again.
If I disconnect the displayport cable the laptop screen works fine and I can swtich to Intel mode in NVidia settings and plug my monitor back in and it works.
Any help would be appreciated, maybe there’s a log file or something I can check to see what’s happening when I it keeps switching?