Hello, I am looking for some help on deciding what Imac I should buy. I have everything down with the exception of the graphics card difference between the models. I am not a gamer. But, I am a techie and I want the best picture possible. So, is it worth buying a higher end card or does it really matter for me? I have own Macs before and I know the ends and outs of them. But, I never learned what the difference is with Graphic cards. I searched Google and I could never find a comparison of the cards available now. Any help would be appreciated it.