AMD Does RAID On a Chip –

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.