Yeah they don't offer a straight SATA setting currently under hwbot, its a choice of raid settings, ide, and ahci.
Apparently there have been a few people messing with ACHI on this platform while overclocking, I haven't tried it with the new bioses. The Previous bios revisions would fail to recognize the drives outside of 100mhz bclk (which is stock bclk). I also found that at about 160+ bclk it doesn't like to try talking with a ssd and a large hard drive.