So I got my 2011 (3.1ghz, i5, 6970m1gb, 12GB RAM) this afternoon. After updating and getting it all setup, I decided to test out some games. I loaded up the first Portal through steam, as I have always owned it, but my old system would never let me get more than 15fps. It looks and sounds well enough, except for MASSIVE screen tearing. I mean, the entire screen up and down has about 10 lines at any given amount of movement. Anyone know why this would be?