I DID NOT format the SSDI will use for "Caching" before I set it up in the Intel software (iRST v10.5...1026).
It worked just fine!
RAID Post now shows the drives as "enhanced" on BIOS post. And in "enhanced mode" in the software. THe drive not longer shows up in Disk Management.
I don't know if it's actually faster, as it's only been up for a day. I have to run things several times before I should notice it. Not ready to start running benchmarks yet. It's still a fresh install.
BTW: It's caching my Data drive. The OS is already on 2 x OCZ Agility 3 SSD in RAID 0. Had the drive, got the mobo for other features, so why not?!!