How to upgrade Mac Pro 5,1 disk slots to SATA 3

Where does a SATA3 go in my motherboard SATA slots? sata 3 slot The PEXMSATA343 3-Port PCI Express SATA Card with HyperDuo adds an internal mSATA SSD slot plus three internal SATA III ports to sata slot Mounting frame for inch SATA hard disk and SSD; Add another internal inch SATA HDDSSD to your computer; Suitable for almost all SATA optical drive

sata 3 slot SATA III x 8, supports RAID 01510 2280 M-Key x 1 (PCIe Gen PCI Slot x 3 30423052 B-Key x 1 Mini PCIe Slot x 1