PCIe Standards: What You Need to Know

In real applications, insert the PCIe card into the host or server PCIe slot

That will work for old cards, but it can't go back to PCIe The riser slot on the motherboard x32? so I tried to Google around From

pcie slot function PCIe Test Cards For testing PCIe slots Learn More Buy · USB Power Delivery Tester For testing USB ports and USB chargers Learn More Buy · Inline PSU Tester Most

pciex1_1 slot x32, where the number following 'x' represents how many channels the PCIe slot has A PCIe x1 slot