According to the chipset specification of GSATA2Sili5723, kindly notice that GS-0 Source and GS-1GSATA ports are as a group and GS-2 Source and GS-3GSATA ports are as a group. It provides you the easiest way to use Smart Backup Function to build RAID 1.
If you connect the HDD in GSATAGS 1 or GS 3 position, it will automatically execute RAID 1 functions to backup the first hard drive to the second hard drive in the operating system. In the other word, GS-0 Source HDD Data will automatically backup to GS-1 HDD. GS-2 Source HDD Data will automatically backup to GS-3 HDD.