What is PCI Express? Do PCIe lanes, slots, and versions matter?

Width Single Slot Recommended PSU Wattage Virtual Reality Ready Core PCIe DirectX 12 HDCP Ready Low Profile Video Card ZT-P10300A-10L + off w

Width x8, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt- On the other hand, show me a fairly recent motherboard without a 16x PCIe slot

pcie training error slot 1 Slot Width Stream Processors Virtual Reality Ready line_back ALL FILTERS ASUS ProArt GeForce RTX 4070 Ti SUPER OC Edition Graphics Card (PCIe , 16GB

pcie 50 slot PCIe Slot Width and Capabilities · Slots 3 and 10 have x16 connectors with x16 electrical interface · Slots 1 and 2 have x16 connectors with x8 electrical