I have an MP 4,1 2009
OSX 10.11.5
HD Setup:
1 X 120gb Intel SSD on PCIE card (named OSX)
Apple RAID card
4 X 2TB Western Digital Red drives in RAID 5 (named RED)
1 X 4TB WD USB 3 External HD (on USB 3 PCIE) Time Machine
I originally setup my RAID as 5 because I thought I needed that last...