Just ordered a i7, 3tb Fusion drive, and 8 gigs of ram. I have read somewhere on this forum about adding ram to what I have (making it 24 gigs). Is this possible, or do I have remove the 8 gigs and replace it with new ram? Where can I buy it? Crucial told me they do not guarantee their ram in the new iMacs. I think this was miss information, I've alway had great success with their product. So where did you buy yours?