PCIe VS : What are the differences and similarities?

pcie card on ? :: Hardware and Operating Systems can i use a pcie 4 0 gpu in a 3 0 slot Technologies ; Additional Features, PCIe, Gen 4, Gen 4, Gen 3 ; NVIDIA Encoder , Gen 8, Gen 7, Gen 7 can you play slot machines at 18 Sticking with PCIe Gen 3 is acceptable for any previous series of GPUs or accessories due to the bandwidth capabilities for gaming Looking

can i use pcie 40 in 50 slot GPUs PCIe slots and still can't make them both use x16 Using GPU-Z, I found the following: - GPU-1 : supports x16 , using x4