We've got a couple of these in our test lab. Look at the IBM part number on the front, make sure all of the letters are the same. It's possible that one doesn't have a raid adapter. The raid adapter is just a plug in DIMM card inside the server. Also if the server has a RSA card look to see that the hardware is reporting via RSA. If I remember correctly these raid controllers only supported raid 0, 1, 5 (??). The raid controller should have 2 channels with your chassis drives on one channel (depending on the disk back plane).
You can update these servers using a bootable CDROM or PXE boot into a DOS shell.
Intel Raid Driver Download
Ibm Xseries 346 Raid Drivers Download
IBM xSeries 346 Servers — Fast, improved 2.8 GHz. Cabling — Standard Non-RAID configurations The xSeries 346 server contains a DASD backplane supporting. IBM's technical support resource for all IBM products and services including downloads, fixes, drivers, APARs, product documentation, Redbooks, whitepapers and technotes.