Will my graphics card work in all PCIe slots?

Additionally, the x16 slot is reduced to x8 when used in this way PCIe x16 Bifurcation is supported to a maximum of three PCI Express devices

PCIe Slot Version

pcie x 16 slot ECN, September 3, 2014 SMBus interface for SSD Socket 2 and Socket 3 SMBus This optional normative ECN defines 3 new PCIe trans view more This

pcie 4 in pcie 3 slot I've filled up my motherboards 8 sata slots and now I'm looking for an HBA to get 8 more Alas, I've only got a pcie x8 physical with x4