All X58 motherboards utilize the Intel ICH10R southbridge which controls the raid functions on the black SATA ports.  The limit for RAID volumes under this chipset is 256TB.

Please note:  Windows XP 32bit and older operating systems have a bootable/system volume limitation of 2TB.  For a storage volume you can have up to a 256 TB RAID volume, but a max of a 2TB volume can be used for an bootable or system volume.