Hi, Posting to clear up a few questions I have. Firstly, I plan to take on the task of formatting and reinstalling the important stuff on my Mac. I have had it coming up to 3 years and it is getting a bit long in the tooth on start up and is not as nippy as my brothers new MacBook. The PowerMac has two 500GB hard drives which came with it when purchased from Apple. Since purchasing I have always had 'Macintosh HD' and 'Hard Drive 2'. I am now considering setting these up in a RAID format so 'Macintosh HD' will show up with 1TB rather than 500GB. Is this worth doing or is it more 'sensible' and 'accessible' to have the two hard drives? Secondly, my PowerMac has 4GB RAM. I am planning on upgrading to 8GB or more. Currently I have 4GB in 1GB DIMMS. Can I use 2GB or 4GB DIMMS alongside my existing 1GB DIMMS, or should they all be the same size. Thanks for any helpful replies.