I have 2 GB of RAM in my MBP and I think it's about time to upgrade! I have a few questions: I would like to upgrade to at least 4 GB...but the question is, do I go 2x2 GB sticks or one 4 GB stick? One 4 GB sticks allows me to upgrade to 8 GB easily in the future, but this means I would be mixing a 4 GB and a 1 GB stick which might "slow" down performance. 2x2 GB sticks are matching sticks (obviously) but it kind of prevents any upgrading in the future. What does everyone recommend? One 4 GB stick by itself or mixed with one of my 1 GB sticks I already have? Or two 2 GB sticks? Thanks! I tried searching this, but I didn't see it in the results!