I got a 27 inch iMac that is currently 1 generation behind. Its got the 3ghz dual core processor and 4GB of Ram that came with it. I read the Applet documentation on the type of memory and just called my local Apple repair center for pricing. To max out the memory it going to cost $540 and to double it to 8GB it would cost $160. I then went to new egg and typed in the right speed and type and found these: G. Skill 4GB G.Skill 2GB I have heard good things about gSkill in the past and they have a ton of great reviews. Couple questions however: Seems silly but these will fit right? Is there any reason to stick with the "Apple" branded memmory? My computer seems to be getting noticiablly slower when I have more and more windows open. This will help me out quite a bit right? Or is my bottle neck at the Dual core processor? Any reccomendations on 8GB or should I go all out for the 16? If I do go with the 8GB do I just need two sticks of 2GB or should I get rid of the factory sticks and stay with one kind/brand? Thanks so much for the feedback!