I have a new Vaio S 15" with Windows 8 pre-installed and UEFI. It had both Intel on-board graphics and nVidia discrete graphics. Installing Ubuntu has turned into a nightmare.
Installing from Live USB with default settings results in a black screen and freeze after the splash screen.
nomodesetin GRUB (this seems fairly common) gets further - but the install then hangs with
fb: conflicting fb hw usage inteldrmfb vs VESA VGA - removing generic driveras the last message.
I can 'Try without installing' and get to the command line with
i915.modeset=0, but I am not sure where - if anywhere - I can go after that. This does not work for the install.
I have run out of bug reports that match mine and not at all sure where to go from here.