Create Raid - ASROCK 775Dual-880Pro Getting Started

3. A message box will pop up to prompt user that the disk array has
been created successfully and ask user whether to restart the
computer. Click "Yes" to restart the computer or click "No" to skip
restarting. New disk array setting will take effect only after
restarting.

Create RAID 1

You can reserve the data on the source drive after clicking "Create"
button when you create a RAID 1 array.
There is a limitation if user wants to keep the data on the source drive -
the capacity of the mirror drive must be greater or equal to the source
drive, otherwise the RAID 1 can't be created.
If user wants to keep data in the source drive, RAID tool will ask user to
synchronize the mirror drive after the system's rebooting.