Please excuse the dumb rookie question, which I have tried to answer by Googling, to save you the trouble and me the embarrassment. I am ready to replace my mid-2010 MacBook Pro -- but want my replacement to be able to pay a few games (using Boot Camp, Windows 10) that are beyond my current Mac. These are modest games (Like Victoria 2, IL-2), not fast-action FPS games. But some require 512MB of video memory. My current GeForce 320M apparently draws up to 128MB, having none of its own. The Intel Iris 6100 apparently also relies on shared memory -- but how much? intel's site does not tell me. The $2500 15" MBP has another graphics card with 2GB of video memory, but I would obviously prefer the $1800 13" version -- if it will handle those games. What do you think? My current laptop plays Civ V but stalls and stutters and hangs up now and then, and is slow to redraw the screen. Many thanks.