I saw (somewhere - can't find the official intel link at the moment) that by selecting RAID in the BIOS and installing the Intel storage driver you still get AHCI on drives that are not in the RAID.
Here's a forum that discusses it http://www.evga.com/forumsarchive/printable.asp?m=100887601
Edit: Derp. I'm sure this is the way it works since my wife's PC has a single SSD plus a pair of HDDs in RAID1. The Samsung utility reports that AHCI is enabled on the SSD. I think I need more caffeine.