I have a Gigabyte GA-P55A-UD4 motherboard and I am attempting to create a new RAID1 volume, but the option for creating new volume is not available in the status screen. Windows 7 64-bit Ultimate, 18.104.22.1686 drivers. The system has one existing RAID1-volume, two new 3TB drivers that I am attempting to use in the new RAID1 volume, one additional hard drive and a DVD-drive (ie. all six ports in use).
What happens, when you hit the "Manage" button? Aren't you able to create the RAID1 array?
If not, have you tried to hit CTRL+I while booting and to create the RAID array by using the IRST Utility?
There is no option for creating a new RAID1 array in manage menu, only options for modifying the existing array or marking the smallest non-raid disk as spare. The boot IRST utility is version 9.5 and does not support 3TB drives.
The missing support of >2TB sized drives will be the reason why you cannot create a RAID array with them. The IRST Console is nothing than a software, but the Intel SATA RAID Controller of your system requires an up-to-date Intel RAID ROM module, which is part of your manboard BIOS. Only Intel RAID ROM modules from v10.6 up do Support HDDs >2 TB.
Solution for your problem:
Ask your mainboard manufacturer for a BIOS with updated Intel RAID ROM or update it yourself. Here you can find a guide about how to do it: http://www.win-raid.com/f16-BIOS-Modding-Guides-and-Problems.html BIOS Modding Guides and Problems.