Need clarification regarding hard disk capacity supported by my motherboard

I have a Gigabyte GA-78LMT-S2P motherboard. On the website it says this motherboard supports 3TB Hard Disk. Does it mean it supports a maximum of 3TB in a single physical hard disk, or is that 3TB calculated by adding up the capacities of more than one hard disk? For example, suppose I already have a 1TB hard disk installed, can I add another 3TB hard disk and will the motherboard recognize the total 4TB? Or will I be able to add only an additional 2TB HDD because the total capacity shouldn't exceed 3TB? Please help me out. I'm confused.

It should just be per disk, not in total (unless you RAID them together, potentially).

usually when a motherboard says something like that, it usually means it is per drive. your using these drives for video-editing right?