The best way to beat the prices if you want 16GB of ram is to buy ram pulled from iMacs off eBay. I just bought some for a great price and will fit it in my new 27 iMac when it's here in a few weeks time. Question, althought the ram will be compatible and should be running in duel channel will there be any benefit using matched ram that was all manufactured in the same batch? Option 1: batch 1240 2x4gb + batch 1248 2x4gb running in duel channel pairs Option 2: batch 1248 4x4gb running in duel channel pairs It would be nice to have fully matched ram. What do you think?