Yeah the point of RAID 5 is to minimize "waste". Storage is the only thing the system will be used for. I want lots of space for video. It will be a server but not running all the time, just when I need access to something.

The processor would be a problem on an old system I'm sure. I will probably end up being a PC but I was curious because I wasn't able to find anything on RAID 5 on a Mac.