There *must* be a place within the BIOS configuration where you select RAID instead of AHCI for the SATA interface. If you cannot find one, you need to contact your vendor's support for more assistance (i.e., call Dell).
Hope this helps,
Thanks. That might be more helpful than what Dell gave me. I'm of the opinion now that this motherboard supports RAID on its SAS connectors, but not on the SATA connectors. Unfortunately my employer provided no options to order the PC with SAS drives or a RAID1 configuration.