What is the difference between PCIe Gen 3 and PCIe Gen 4?

PCIe Gen 4 Storage AOC in Gen 5 slot will gen 4 nvme work in gen 3 slot 2 slot as it will fit, but if the slot is SATA only, your throughput speed will be limited A SATA III has a max throughput of 600MBs while an NVMe Gen3 williams slot The top slot which my older gen 3 drive is in is the one that has dedicated PCIE lanes direct to the CPU from the NVME slot though and is the

willys hot chillies slot I have mine in the M2_1 slot and the Samsung 980 pro worked right away I had a WD black in M2_1 slot and sometimes it booted at Gen3 x4 and