m.2 not recognized with new cpu

[chriswill16]

Upgrade from a ryzen 5 5600g to a ryzen 7 5800x and my top m.2 slot will not recognize my drive.

the cpu post but the top slot m.2 drive want recognized the drive.
the only way to boot into the os is puting my m.2 in the bottom slot.
when i put the old cpu back in both m.2 works.

[Aaron_T]

Not going to lie, this is a weird one. These CPUs should be 100% compatible with every component on your platform.

The top M.2 slot is likely the the 4 PCIe lanes connected directly to the cpu. The rest of the M.2 slots are probably connected through the motherboard controller chip.

 

This means the likely issue is that the new 5800x CPU has an error with the PCIe pins/lanes that connect to the top M.2 slot.

 

EDIT: do you have access to a different (3rd) CPu to test with, or a second motherboard to test with?

[chriswill16]

Don't have 3rd cpu, motherboard to test with