Hey, I intend to order a 27" i7 iMac soon and when I do intend to get the 4gb version with the intension of upgrading to the full 16gb for my video editing. I've read how it's advised to use paired Ram so I was going to buy 4x4gb of Crucial/Kingston or whatever. Before I do I just thought I'd check - is it fine to completely 100% change the Ram in the iMac? The process looks pretty simple and therefore in my plan I'll be putting in a fresh 4x4gb modules all of the same genesis. But before I do I just thought I'd check it's fine to have all new ram in the machine. Cheers!