The Alienware M18x, also identifiable by its model number R2 AM18XR2-7778BK, is a gaming laptop manufactured by Dell in 2011 with an 18.4 inch screen. It has a 12-cell lithium ion, 3 Megapixel resolution, and Microsoft Windows 7 Home Premium 64-bit Edition.
Hi Pepin Menéndez
Suggest you to open up and check.
Seems on the net, the mainboard has MXM slots.
and while searching, there is sellers selling those replacement graphic cards.
Augustine さんによる