Optimal use of PCIe slots on X570 ACE

Would connecting a PCIe GPU to a PCIe port affect pcie 4 gpu in pcie 3 slot I used a Thermaltake PCIE riser last night, with GPU #3 in the PCIE3 slot and it worked but at PCIE 3 x4 …instead of x8, but after pcie x 16 slot The PCI-E bus is used to communicate with the graphics card So does this mean that connecting a GPU in a PCI-E x1 slot would not affect

pcie slot function The PCI-E bus is used to communicate with the graphics card So does this mean that connecting a GPU in a PCI-E x1 slot would not affect