Processors

[spark_tornado]

MSI x570-a pro MB, Ryzen 5900x supports dual channel but not Ryzen 5950x.

SLOT A1 and A2 are not working but B1 and B2 works fine.

If there is a RAM in B1/B2 and A1/A2 it just doesn't POST. No display.

[goodplay]

A2/B2 is the norm, install A2 first then B2 is usually mentioned in mobo manual.

For 4 ram modules make sure it is a kit and compatible with mobo/cpu combo on the msi site list.

[spark_tornado]

I started with A2, as soon as there is a RAM in A1/A2 slot, it wont boot.

[misterj]

89spark_tornado, unless you have some funny/bad memory looks like MB RMA time to me. Enjoy, John.

[spark_tornado]

Thank you, could this be a CPU issue instead of MB because all slots work with 5900x CPU.

[misterj]

89spark_tornado, well it could be. I had problems with losing memory controllers and RMAed the processor but got the same errors.  I tend to believe MB first, RMAed several some more than once. Have you checked out AMD Specifications? Please check it out and if OK I suggest you talk with your MB vendor. Thanks and enjoy, John.

[MADZyren]

If system works with another CPU but not with this one:

1) Make sure your BIOS version supports this new CPU
2) Could well be an issue with CPU - maybe some CPU pins are damaged or something wrong with memory controller in CPU