I'm helping someone set up their G5 Quad system and she configured it to have two 500 gb internal SATA drives, which is pretty useless for her needs. Start-up, applications and FCP project files are on the primary drive; and media is on the secondary. Which means that most of her 500 gb on the primary drive goes unused, because she can't put any of the media on that drive. So, what I'm wondering is: can you run Mac OSX off of an external FW drive. Mac says it's fine, and that external FW drives actually run slightly faster than the internal SATA drives anyways.