I will be getting one 500GB boot drive to hold the system and all my apps. Yes I really need all of that space for all of my applications. Then I will be getting 3 750 GB SATA drives to go internally into my mac pro. I wan't to raid those 3 drives in a stripped array mainly for video editing storage. Will raiding 2 750 GB drives provide less storage space than raiding 3 750 GB drives? When you RAID two 750GB hard drives what will the final storage space be of the stripped array? Thanks for all your help and I would appreciate a response. Thank you!