The SS-SA2R supports two serial ATA ports, it supports 2 serial ATA devices (one for each) or can connect more devices via Port Multipliers. It provides complete software driver and RAID KIT. It is the right choice for a PCI Express to Serial ATA versatile devices.
Silicon Image Does Not Provide Boot Capability for Their RAID 5 software. If you Need Raid 5 Please consider a true Hardware System, there is NO Cheap Solution for Raid 5. ANy Raid 5 card that is prices less than $500 is not a hardware Raid card (host adapter). Silicon Image RAID 5 is software based and is very limited, please read silicon image site for more information.