I have a 2007 model 8-core Mac Pro, which I ordered with one 750 GB hard drive. Now that hard drive has less than 10% free space, and it's time to throw a second drive into my machine. I am wanting to get a 1TB drive to supplement the original 750GB drive - will I be able to set up a mirrored RAID (RAID 1) when the two drives are of different sizes? Also, when it comes time for a third hard drive (another year maybe), will I be able to incorporate the third drive into the mirrored RAID? Or can it only be done with an even number of drives? One more thing: are there any other RAID configurations that would be more beneficial than a mirrored RAID? My Mac Pro is a photography computer, and offhand I thought the mirrored raid would be ideal in case of a hard drive failure to save all the photos... Please advise.