Hello all, I recently placed a BTO for a new 5K i9 iMac to replace our Late 2009 model which was becoming frustrating as it took a few minutes to load Safari. I was wondering if there was any specific model of external drive I should buy to use as our Time Machine backup. I looked on Apples website and the selection was fairly limited so I figured I would ask for advice from the people who know the best. Thanks in advance! Cheers!