Can a PCIE 3.0 Riser Be Used in a PCIE 4.0 Slot
For example, a PCI Express 4.0 graphics card works even if you connect it to a motherboard that only supports PCI Express 3.0 or even 2.0.
HP 22-2027d All-in-One Desktop PC product specifications
GA-B250M-D3H · 1 x PCI Express x16 slot, running at x16 (PCIEX16) * For optimum performance, if only one PCI Express graphics card is to be installed, be sure to ...
Amazon.com: StarTech.com 4-Slot PCIe Expansion Chassis w/PCIe ...
From the manual of the Lenovo M93p (http://content.etilize.com/User-Manual/1029184064.pdf): The motherboard has 3 PCI Express slots: a "PCI Express x16 graphics card slot" a "PCI Express x1 card slot".