3.4GHz Quad-Core Intel Core i7 4GB 1333MHz DDR3 SDRAM - 2x2GB 2TB Serial ATA Drive + 256GB Solid State Drive AMD Radeon HD 6970M 2GB GDDR5 Magic Trackpad AppleCare Protection Plan for iMac- Auto-enroll Apple Remote Apple Battery Charger As per the advice of the members of this forum, I am opting to purchase RAM from elsewhere. I have noticed that people have been having trouble with OWC RAM and their iMacs, so I'm avoiding that (there is also the fact that OWC does not make its own RAM so it is difficult to know what brand they will ship out to you). Since 16GB may be overkill, I want to bring my iMac up to 12GB... So, my questions are: 1. Which brand? Crucial? Is the RAM at this link good? 2. Is there a certain combination that is better than others? For instance, should I get another 2x4 or should I get a single 4GB stick? Will the performance suffer if I get another 2x4 set instead of a single 4GB stick?