Hey guys I want to set up my Hard drives in a RAID 5 config, where info from my 2 main HDD is stored on the third and can be pulled in case of a HDD failure. How big does the third HDD have to be, does it have to be the same size(300gigx2) and writing speed(10000 rpm) as my two actual HDD? Or can it be smaller(80gig) and with a slower (7200rpm)