My HP Envy 17t meets system requirements for a virtual reality application I want to use, except for the graphics card. I understand that there are commercially-available devices which allow attachment of an external graphics card to a notebook, as discussed here: http://www.notebookreview.com/howto/how-to-upgrade-your-notebook-with-an-external-graphics-card/ I'd like to know if any of these devices could allow me to use an external NVidia 970 or AMD R290 with 4GB dedicated video RAM with my notebook?