What does the X4 mean in an PCIe Gen X4 NVME drive?

2 slot would the ADT-Link R43SG setup run at 32Gbps or 64Gbps? I have heard that high quality gen 3 cables could transfer at gen 4 speeds but

PCIe maintains both backward and forward compatibility with older and newer specifications 3; 4; 5 PRO H610M-E DDR4 Support Intel® Core™ 14th 13th

pcie 8x slot PCIe Gen 4 is backward compatible, so a PCIe Gen 4 device connected to a PCIe Gen 3 system will function normally at PCIe Gen 3 speeds That means if you

pciex16 slot configuration Slot are either PCIe or depending on riser selection and rear drive bay selection The use of some slots requires two processors Slots are configured