I am running a 2.3 GHz MacBook Pro and currently I have a 200 GB 4200RPM internal drive (impossible to edit video with), but I only have about 45 GB free on it and am looking for an upgrade. My main goal of the upgrade is to be able to realistically edit with Final Cut Pro on the internal drive (both speed and storage space). I have two options, either a 320GB drive @ 7200 RPM or a 500GB drive @ 5400 RPM. I am only dealing with compressed SD footage and Motion graphics. I also do not want to get rid of any data from my internal drive (most of it is my iTunes library which I often use for editing), so which drive would be the best option? Or please let me know if a SATA 7200RPM 500GB drive exists. --Thanks.