DDR5 4 dimms on am5

Both LPDDR4x Memory and DDR4 Memory can be found in laptops LPDDR4x Memory offers better power efficiency at the cost of performance

Just to clarify DDR5 is not backwards compatible with DDR4, it's a completely different DIMM slot There will be DDR4 and DDR5 Alder Lake

cantik 4d slot DDR2 memory can be installed in pairs to run in dual channel mode, which can increase memory throughput even more DDR, DDR2 Prefetch, 2 - Bit, 4

can you use a pcie 40 nvme in a 30 slot No, the slots are physically incompatible so you can't accidentally insert DDR4 into a DDR5 slot