Can someone explain me the PCI-E slot variations & sizes of

Item 4 is the PCIe slot 4, on Riser 2 and is connected to Processor 2, it supports a full height, full length 16x card The slot width is 16x Item 5 is the

*When using a PCIe x16 add-on card, the length of the card must not exceed 167mm or inches Automated Inspection Machine Application

pcie slot size PCIe x1: has 1 lane, 18 pins, and 25 mm in length · PCIe x4: has 4 lanes, 32 pins, and 39 mm in length · PCIe x8: has 8 lanes, 49 pins, and 56 mm

pcie x16 expansion slot Card capacity and size · Slot 1: gen 4, up to x16 lanes · Slot 2: gen 4, up to x16 lanes · Slot 3: gen 4, up to x8 lanes