Bad batch of DDR5 memory or something else?

can you run ddr4 in a ddr5 slot   Dan can i use pcie 30 in 20 slot

If you have two memory bars in four slots, you should use the second and fourth slots If you have four slots and four memory, you should

Both DDR4 and DDR5 modules have 288 pins and do not share the same pin layout Thus, the DDR5 DIMM will need a new slot However, like DDR4, Although DDR5 retains the 288 pins from DDR4 , the notch has been shifted to the left

fire and ice slot machine Given the difference in voltage requirements and other crucial modules, DDR5 RAM is physically incompatible with DDR4 slots Because of this, Due to the unique electrical architecture of DDR5 DIMM, there's a high risk of damaging the memory module if AC power isn't disconnected properly during removal