To answer your OP, YES.
However, the controller in BIOS must be set to RAID, to use RAID. But you don't have to set up all drives into a RAID array.
If you have a SSD drive, you wouldn't add it the the array, only the HDDs. ANd TRIM would be supported with Windows 7 for the SSD.
I believe, and I could be wrong, if the SATA controller is set to RAID, and a drive on that controller isn't in a RAID array, it defaults to ACHI.
sminlal refers to if you have 2 SATA controllers on the motherboard. Yes, they are out there. My Asus P6T has it. 6 SATA ports for the Intel ICH10 controller, and 2 SATA ports for the JMicron IDE/SATA controller. (I don't ever use the JMicron SATA ports!)
What motherboard do you have?