can you use them all at once? it looks like 6 are on a regular drive controller and 6 are on a raid controller. sometimes you can't use both drive controllers at the same time. but if you can use all 12, i'll have to look into getting that motherboard next
my Lian-Li case has 12 internal 3.5" bays and 7 external 5.25" bays. it would love that motherboard