Dedicated Graphics Cards

The internal graphics chip would still be there, and a port along the back usually. Why wouldn't it?

http://www.pcworld.com/article/2984716/laptop-computers/how-to-transform-your-laptop-into-a-gaming-powerhouse-with-an-external-graphics-card.html

Ever see that movie "Sandlot"? And the kid asked "Who's Babe?" and everyone gives him that "duh?" look? That's sort of the way I felt when I saw this question, but also realized it's one I'd never heard before.

are compatible with the graphics amplifiers actually have integrated Intel graphics. The integrated graphics is on the Intel I-series processor. Being gaming machine they also have either the Nvidia 960,970 or 980 dedicated graphics cards. The amplifiers are sold separately and their are at least 2 companies thay make them (Alienware and Asus for thr ROG Laptops) The laptops also have the ports to connect the external graphics card. These graphics amplifiers aren't specific to one graphics card and you can use any quality you wish. The advantage of this graphics amplifier is the heat source is outside the laptop case and the lifetime of the laptop should be longer.