Asus P5BV/SAS User Manual page 105

Select RAID from the Logical Drive menu, then press <Enter>.
6.
Select the RAID level from the menu, then press <Enter>.
7.
You need at least two identical hard disk drives when creating a RAID 1 set.
When creating a RAID 1 set, select DWC from the Logical Drive menu, then
8.
press <Enter>.
When creating a RAID 0 set, proceed to step 10.
Select On to enable the Disk Write Cache setting, then press <Enter>.
9.
Enabling DWC can improve the performance, but with the risk of data loss.
ASUS P5BV Series 5-7