Thanks for the detailed advice
As it turns out, it was a small issue causing the big mystery. The seller shipped the tower with the optical drive connected to a row of SATA ports with 2 dark grey ports(where the DVD-RW was connected) and 4 white SATA ports. All the way down to the bottom edge of the motherboard, there is another row of SATA ports called SAS ports and the 4 hard drive bays were connected there. Once I connected the optical drive to that row of ports, everything works as expected. Now that that issue is solved, the Z820 is shaping up to be a damn fine PT rig
