This thing is FRAID or software raid. It’s no better than ICHx or any other chipset based “raid” system. When you see somehting like this:
Dot Hill’s RAIDCore technology enables host-based RAID 0, 1, 5, 10 and 50 directly on motherboard SATA I/O ports, and the same software stack with additional features enabled may also be used for SAS systems that use a built-in or PCIe host adapter-based SAS/SATA chipset.
Also a bit a googling reveals a small thread where I already researched this:
The host based is what gives it away. Anything that is host based puts the processing load on your cpu. In the case of RAID 5 or 6 that load is high. Never turn this garbage on..use a real RAID controller.