PCIe X8 vs X4 slot speeds for 10Gb fiber

PCIe to PCI Express x16 Bifurcation Adapter Card; Four IPCIE16XD11-8---Two SFF-8654 4x Receptacle Connectors to PCIe x16 Slot Adapter Board

PCI-e 1X4X Open Back Card to M Key 4 Lane PCIe Slot Adapter Micro SATA Cables PN # M2-921-1X4X

4x pcie slot The specs state that the PCIEX4 and PCI Express x1 slots conform to PCI Express standard In which PCIe slot did you drop the to PCIe x4

4x4bet slot It's a slot of x16 size but electrically x4 This