can we install PCIE x16 graphics card in PCIE

Is a MacPro3,1 x16 slot PCIe or ? pcie 2 slot A PCIe lane is a single data channel within a PCIe slot Introduced further doubling of data rate per lane compared to PCIe , providing higher performance pcie 2 slot Pretty much, its a 16x slot that runs at 4x electrically which means its going to have 14 the bandwidth You are going to lose a lot of

pcie2 slot Table 1 provides information about the PCIe slots in the 8247-42L system that offers both a single POWER8® processor module or two POWER8