see also:
http://forums.lenovo.com/t5/Linux-Discussion/64-bit-Linux-W520-amp-nVidia/td-p/577789
with discrete graphics & nouveau the boot is also instable, did turn off VT-d in BIOS
see also:
http:// forums. lenovo. com/t5/ Linux-Discussio n/64-bit- Linux-W520- amp-nVidia/ td-p/577789
with discrete graphics & nouveau the boot is also instable, did turn off VT-d in BIOS