Guys I need your inputs regarding this: I upgraded the HD of my MB (late 2008) to 640GB. I currently have 2 Partitions, System and Data. The only reason why I did this is because I have 2 250GB external HD and I always want to have I cloned copy of my System and Data Partitions. Now, Im planning to get a 1.5T external HD drive, is it a good idea to just have a single partition on my MB and clone it on the one of the partitions on 1.5T HD? will it slow down my system? btw, I am running SL 10.6.4 with 4G of RAM if this is a factor.