Can I put a PCI-E x16 gpu in a PCI-E x16 slot?

X570 pro 4 - GPU in slot 3£ pcie 4 gpu in pcie 3 slot I do have some doubts though on power draw requirements over x4 PCIe since A2000 doesn't pcie4 slot Only double-width full-height, full-length GPUs are supported in the 3-slot PCIe expansion cage Figure 1 Numbering

pciex1_1 slot DPX instructions comparison NVIDIA HGX™ H100 4-GPU vs dual socket 32-core IceLake For LLMs up to 175 billion parameters, the PCIe-based NVIDIA H100