Hi I have the 21.5" 2.5Ghz Quad Core i5 model of the iMac, I have seen 2 different options on Apple's website about this, and was just wondering if maybe you guys could clear it up. My iMac came with 4GB of ram, according to the Specs when I bought it, it said 8GB was max, however I just looked at Apple's instructions on replacing ram and it said the max ram for my iMac was 16GB. So which is it??