Ok so I bought a new iMac on Tuesday. I know the new one is suppose to come out soon but I couldn't wait any more. And I'm wondering I got the 27" iMac from best buy its graffix card is amd radeon hd 6770m 512mb gddr5 and I Wa wondering how good it is at gaming I don't plan on running games on ultra settings but med-high is good enough hopefully. And it has 4gb of ram but I was wondering whats the point of putting more ram ini it be what it would do for gameing.