hello. my interest is video editing. i want to get serious with it. i use final cut pro and motion. i am going to buy a new iMac soon and iwant to get a powerful machine to edit, better than a macbook pro. but i cant figure out how the gpu will effect video editing? i dont play video games, i just edit video and have a lot of things open all the time. does it make the rendering faster? exporting faster? if the gpu has nothing to do with video editing i was going to get the 21.5, i7, 16ram, and gt650m gpu. i dont get it. can someone clear this up for me? thanks.