I'm not sure if this is correct. On my desktop, I have an old ICH8. The Rapid Storage/Maxtrix still supports RAID volume greater than 2 TB. So if I have a 6 drive RAID, then it would limit each drive to be 400GB?
I believe the link you sent refers to the 2TB disk limit, not the volume limit. The RAID is at the BIOS level. Regular BIOS can only see 2 TB disk. So most of the BIOS level RAID controller can only see 2 TB diskS.
But at the operating system level, OS can see GPT partition. So product like Windows Storage Space should be able to use all large HDs. So we should be able to build a 3x5TB software array.