Hello!

You can get into the RAID setup by pressing ctrl+i on the post screen.

You could go to the BIOS and check the following configuration

Advance> integrated devices> sata mode> ISRT

If you have it on AHCI you might not see the ctrl+I option, but as soon as you change it to ISRT it might not boot and you will need to start  with a clean installation of windows

I tried CTRL + I multiple times & it doesn't work

Under Advanced >> Integrated Devices, I only have the following options listed:

USB Controller [Enabled]

HD Audio [Enabled]

Onboard LAN Controller [Enabled]

Primary Display [Auto]

PXE Option

PCIE GEN3 [Enabled]

There is no SATA Mode option or ISRT option on that screen.

I do have the Boot mode set to Legacy.  I did change it to UEFI & rebooted but SATA still was not listed & the CTRL+I didn't work either.

Yes it is on the latest revision (downloaded & flashed yesterday).

Have you tried flashing the BIOS? 

That doesn't help.  I do not have any RAID options in the BIOS.

I found an article that might help you.

Let us know how it goes.  

I was checking with engineering and they said that the X51 does not come with Raid configuration. That is the main reason why you are not able to get into the raid controller.

In that case what you could try is using the Intel rapid storage technology software to see if you can enter into the configurations of your hard drives and change them as you need.