Have a system w/ ryzen 9 3900x that fails lengthy memtest with 10-14 errors, bit 400 gets inverted, slightly more often it's 1 when should be 0. No other bits have issues. New, faster DIMMS have been installed, and tried in different slots, errors remain. 70% of the errors are on addresses that end with EB4 or FB4, remaining 30% all end with 0, in the range 14289MB - 14515MB.
Is there a handy diagnostic to run to determine if the CPU is the culprit? My very limited experience is that bit inversion happens in ye olde processor...
