I think, only think, that i start to understand exactly what problem have entered the "infamous" F4 Bios. Seems to be the voltage adjust in IOH Core. Before, i just had to set this setting in Auto (1.1000v in ET6), @ 19x211, F4j, for thousands of Linpack x64 pass. Now, i begin to achieve stability by raising the voltage to 1.2000v, in F4j. Anyway, itīs early to be sure.