What is the largest hard drive a Mac Pro 3,1 (earily 2008) will support?

What is the largest internal hard drive a Mac Pro 3,1 (earily 2008) can support?

I read here that it's around 1.2 TBs is that correct? Also I plan to run Proxmox on it, not Mac OSX (well I might run it as a VM...but not directly on the bare metal)