Thanks for your reply.
Sadly my BIOS does not support UEFI
I have tried the Rapid Storage software and the Matrix Storage console. Latest versions from Intel. I can create my large volume using this software but upon reboot I get disc incompatible by RAID boot software.
The Matrix Console gives me the attached error why I try and create my large volume...
Does my OROM simply not support a volume larger than 2TB?
There is little public info available what are the differences between all the IRS BIOS versions. The warning message in the picture seems to indicate that your RAID BIOS is not able to handle disks larger then 2TB.
As I understand it correctly Intel provides the RAID BIOS to other vendors to integrate it. You could ask Dell service what are the limitations of the current BIOS and if they are planning an update.
Your RAID configuration would probably work if you would boot Windows from another disk and use your RAID 10 as D: