I run v4.6 and use random ram combos I got off of fleabay without issue
on my various opteron boards it might be something else - does the
propriatary BIOS have an issue with them?
FYI you need microcode updates with the 43xx CPU otherwise you will have
critical security issues, microcode updates may be wanted for spectre
anyway. With libreboot you can use the OS early loading mechanism.
41xx CPU's don't work well and are very slow, they lack IOMMU code so I
suggest not using them and of course then you would not be able to use
qubes due to no IOMMU.
4386 is the best cpu available and the only one that can play games at a