Hi Borislav, i disable/enable C6 Core with the attached python script via MSR, because i can only disable all C states in Supermicro AMI Bios. Yes, the system isn't completely stable with idle=nomwait. During heavy load changes from idle to heavy load after long high load periods i have seen also with idle=nomwait the same system resets. Therefore i have disabled C6 Core. After that i couldn't replicate the problem. But it is only experimental found. Maybe the crash is not C6 state related and there is another reason responsible for this crash. Best, RK