P67 Extreme 4 Gen 3, two 3TB drives, can't do RAID1?

This is from your motherboard specifications " 2 x SATA3 6.0 Gb/s connectors, support RAID (RAID 0, RAID 1, RAID 10, RAID 5 and Intel® Rapid Storage), NCQ, AHCI and "Hot Plug" functions ".
"2 x SATA3 6.0 Gb/s connectors by Marvell SE9120, support NCQ, AHCI and "Hot Plug" functions (SATA3_M2 connector is shared with eSATA3 port)"
Probably you don't have to use the Marvell USB connectors.

The two 3TB drives aren't connected to the Marvell connectors, they're in the two SATA3 6.0 Gb/s connectors (labeled as SATA3_0 and SATA3_1 on the motherboard). The drives model # is ST3000DM001, by the way.

Someone elsewhere on Tom's informed me that to set up RAID1 in BIOS I need to switch the BIOS mode from ACHI to RAID which will allow me to still have the SSD as ACHI but also use RAID for other drives. So when I get home I'm going to try that, but if I'm unsuccessful I'll try that registry hack.

On 3TB HDD you really should use GPT (not MBR); GPT = GUID Partition Table.

IMO I strongly advise you to create a custom GPT Flash Drive installer and in addition add the Intel RST driver "SATA RAID Driver (For system to read from floppy diskette during Windows installation)" uncompressed to the Flash Drive in a Folder called 'RAID' in the top directory. Next, when requested for the driver open the folder 'RAID' and select the appropriate, I assume, 64-bit drivers.

Download SATA RAID Driver (For system to read from floppy diskette) -> http://www.asrock.com/mb/download.asp?Model=P67%20Extre...

GPT Guide -> http://www.overclock.net/t/1156654/seans-windows-7-inst...

Preparation:
* Backup data
* Use the latest BIOS and you must use a minimum BIOS version which supports 2TB~3TB
* Create Bootable Flash Drive GPT USB installer
** Flash Drive -> http://www.youtube.com/watch?v=H4CdEZPTPzk
** Installer -> http://www.youtube.com/watch?v=39qPm1rNnWk
** Nice guide -> http://www.overclock.net/t/1156654/s...-for-ssds-hdds
* Create a folder on Flash Drive e.g. 'RAID' containing extracted Intel RST drivers

FIX:
1. BIOS:
A. Ctrl + I -> Deleted RAID
B. Intel SATA -> RAID
C. Ctrl + I -> Setup RAID; before OS if boot drive

2. Boot from USB, select 'Install Windows'
A. Load RAID drive from 'RAID' folder; example: 'Flash Drive':\...RSTe_V3002003_XPWin7\RSTe_V3002003_XPWin 7\Driver\Disk\64bit\iaStorA.inf
C. Delete any partitions, and reformat
D. Install Windows
E. Finish Windows installation
E. Install Intel RST software

3. BIOS:
A. Ctrl + I -> Setup RAID; if data drives

4. Windows:
A. Management, Disk Management -- add drives and format.

Good Luck!  

Best answer selected by dragon164z.

It seems that this was the solution, however instead of making the registry changes myself I used RAIDFix to do it for me. Before running RAIDFix when I changed AHCI to RAID in the BIOS I'd get a blue screen before Windows failed to load. Indeed the problem seemed to be that I'd installed Windows in AHCI before setting up RAID. After running RAIDFix (which simply automatically installed missing drivers and registry entries) I was able to set up the two 3TB drives with RAID1 in the BIOS. Everything now appears to be working correctly.

It still seems like I can't mirror the drives with Windows 7 if I wanted to, but now that I have this working I won't need to. Thanks for your help!

Jaquith: Thank you as well. I'm assuming that that would have worked as well and what I did was just the fastest way to do it, but I could be wrong.

This topic has been closed by Nikorr