MGM a new interface for Asus laptop video card module
MGM is similar MXM interface, it is new design for video module card. Now Asus laptop is use MGM at frist and big raise up performance in graphics.
More Laptop would be support MGM slot on future, however MGM could be upgrade in laptop, if  the bios is support.
MGM have instead  MXM module to be main video module type.