The mother board controller is SATA and will not reconize a SAS drive.
You install the one of the optional Intel ® I/O Expansion Modules for SAS
Intel web site it says that this server can do both either SAS or SATA drives.
Can you post the link to this site. It appears that it is confusing to you, so I would like to see if we can get it fixed so as to not be confusing.