need some help with my ASUS M3A motherboard

I have 3 SATA HD's and I want to run the first as system drive and then run
the other 2 in a RAID0 array but after following the directions in the
manual I can't seem to see how to set the first drive to function as a
single primary drive... I am only given the options of setting up RAID0
RAID1 or RAID10. I tried setting up the RAID and then leaving the single
drive unassigned but then the BIOS doesn't pick it up in the boot sequence.
From what I'm reading (and I may be wrong) it's either all RAID or none at
all.

Can someone help me see what I'm missing?

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