In order to get Siemens NX 10.0 working on with official Ubuntu 14.04 factory installed by Dell on Vostro 5480, simply run:
nvidia-settings
And select the option to use de Nvidia video card.
I was first intrigued with this:
$lspci
00:02.0 VGA compatible controller: Intel Corporation Broadwell-U Integrated Graphics (rev 09)
08:00.0 3D controller: NVIDIA Corporation GM108M [GeForce 830M] (rev a2)
By default, the system uses a lower performance GPU, which does not work under NX. By selecting NVIDIA card on nvidia-settings, NX rendering works!