Motherboard Rear IO and PCI-SLOT measurements

My first motherboard runs the 3x full size slots in a PCIE 4x configuration, with the single slot at 1x configuration This new

PCIe expansion slot definitions ; 1 · PCIe , FL, FH · x16, 16, 8, 4, 1 ; 2, PCIe , HL, HH · x8, 8, 4, 1

pcie 40 gpu in 30 slot 1 slot = 20mm, with the width of 110mm

pcie x1 slot function PCIe network cards are designed to fit into larger slots , but they cannot fit into smaller slots; for instance, an x8 card