We have an old server that I want to re-purpose. It currently sits in a Supermicro 3U SC836TQ chassis, with a 16 port direct attached SAS backplane. We want to fully popular the chassis with 16 drives and RAID them. My question is, what is the most cost effective way of doing this? A 16 port RAID controller card, or a expander backplane and a standard 8 port controller card?