Just got myself a 2011 iMac i5 27" and wanted to up the RAM to 12GB. From my research, the "specifics" to look out for are DDR3, 1333, and 204pin. A previous poster led me to this: http://www.newegg.com/Product/Product.aspx?Item=N82E16820231295 which I just ordered. But then I came upon this thread and posts: "After reading up on it some more alot of people say this ram will work with the 1333 ram, all it will do is downclock the factory one from 1333 to 1066." "As the first comment that answered your question, the 1066's will work. But you're adding the risk of having two different RAM combos in your system which has been known to cause startup and OSX errors." I'm starting to second guess myself that I got the wrong/right RAM? Can somebody just verify that I'll be okay and not at risk to downclock or startup errors? Sorry, I just don't know RAM that well, thanks so much... and absolutely loving this iMac, even with 4gb right now.