Riser with Three PCIe Gen3 FH slots One x16 and 2 x8

What is PCI Express? Do PCIe lanes, slots, and versions matter? pci e slot When I was young, I used a software called everest to check the hardwares and most of the time, it could tell me tons of information Seems it pcie 40 in 30 slot Riser with Three PCIe Gen3 slots 1 x16 FH 1 x8 FH and 1 x8 LP at least 2 processors R740XD CusKit The Riser from Dell™ fits into

pcie slot gpu SuperSpeed Storage：PCIe x4 Connector; EZ-Latch：PCIe x16 Slot with Quick Release Design; Fast Networks：GbE LAN; Extended Connectivity：DP, HDMI; Smart